1.
.
.
 Anterior angles of clypeus small, hidden below the external tubercles of the frons. Clypeus hidden below frons (fig. 1), if slightly visible then clypeus is nearly vertical. Frons frequently punctate (tribe Passalini)
.
.
2
 

1'.
.
.
.
.
.

 Anterior angles of clypeus well developed and visible, when not very visible (some Pseudacanthus), then frontal-clypeal suture is obvious at least in anterior view (figs. 21, 22). Clypeus usually exposed, visible dorsally, at times separated from the frons by a suture (figs. 18, 19, 20, 23, 26, 28, 29, 31, 34, 35). When suture not present, the frons-clypeus lacks punctures (figs.15, 24, 25, 30) (tribe Proculini)

.
.
.
.
.
11
Heads of:
Figure 1. Passalus
(Pertinax) sp.
Figure 15. Verres
hageni
Figure 18. Petrejoides sp.
Figure 19. Popilius eclipticus
Figure 20. Undulifer incisus
.
Figure 21. Vindex sculptilis
.
Figure 22. Pseudacanthus subopacus
Figure 23. Spurius bicornis
.
Figure 24. Veturius sp.
.
.
Figure 25. Publius sp.
. .
.
Figure 26. Chondrocephalus purulensis
Figure 28. Odontotaenius striatopunctatus
.
Figure 29. Oileus
sargi
Figure 30. Pseudoarrox karreni
Figure 31. Gen. nov. 2
.
Figure 34. Heliscus yucatanus
Figure 35. Coniger ridiculus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2(1). Apex of maxillary lacinia unidentate. Antenna with 5 lamellae
3
 

2'.
.

Apex of maxillary lacinia bidentate. Antenna with 3 lamellae, rarely 4 or 5

.
5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3(2).
.
.
.
.
. 		Anterior border of ligula tridentate (fig. 2). Median Frontal Structure (MFS=area in center of head usually with some form of horn or protuberance) similar to that of P. interstitialis (fig. 11) or P. punctatostriatus (fig. 1). Frontal ridges and internal tubercles present, if not, and MFS is “striatopunctatus” type, then central horn reaches anterior border of head
.
.
..
0
.
4
 
3'.
.
.
.
 Anterior border of ligula unidentate (fig. 3). MFS similar to that of Passalus plicatus (fig. 14), without lateral tubercles, central horn does not reach anterior border of head. Frontal ridges and internal tubercles absent

.
.
.
Passipassalus

Figure 2. Ligula of Paxillus leachi
.
Figure 3. Ligula of Passipassalus buhrnheimi
Figure 11.Head of Passalus (Passalus) interstitialis “Neleus” group
Figure 14. Passalus (Passalus) plicatus “Petrejus” group
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4(3).
.
.
. 		Prosternellum pentagonal, with posterior border of pentagon longer than half of the maximum width of prosternelum (fig. 4). Humeral angles of elytra glabrous or pubescent. Anterior femur without marginal groove ventrally on anterior border


.
Paxillus
 

4'.
.
.
.
.

Prosternellum rhomboidal, if appears pentagonal, then posterior border is narrower than half the maximum width of Prosternellum (fig. 5). Humeral angles of elytra always glabrous. Anterior femur with marginal groove ventrally on anterior border (Antilles, South America)
.
.
.
.
Spasalus
Fig. 4: Prosternellum of Paxillus
Fig. 5: Prosternellum of Spasalus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5(2).
.
.
.
.
.
.
.
Anterior tibia as wide at apex than at base (fig. 6), with transverse striae on ventral face. Anterior border of labrum concave with an obtuse central projection (fig. 8). Mandibular apex bidentate with superior tooth large and inferior tooth small, rarely with the superior tooth divided or, in South America, tridentate. All tarsi usually short, less than half the length of the tibia (Arizona to South America)

..

.
.
.
.
Ptichopus
 

5'.
.
.
.
.

 Anterior tibia nearly parallel-sided, apex less than twice as wide as base (fig. 7) usually without transverse striae on ventral face. Anterior border of labrum straight, slightly concave or bi-emarginate (figs. 1, 9). Mandibular apex with 3 sub-equal teeth, if 2, then clypeus vertical and easy to see. All tarsi long, length greater than half the length of tibia
.
.
.
6
Figure 1. Head of Passalus
(Pertinax) sp.
Figure 6. Anterior tibia of Ptichopus angulatus
Figure 7. Anterior tibia of Passalus sp.
Figure 8. Head of Ptichopus angulatus
Figure 9. Head of Gen.
nov. 1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6(5).
.
. 		Mandibular apex tridentate. Clypeus below frons, not exposed, difficult to see even from front (Mexico, Central America, South America, and Antilles)
.
Passalus
7
 

6'.
.
.

 Mandibular apex bidentate. Clypeus vertical, exposed, in dorsal view slightly visible but easy to see from the front (Northern Mexico to Nicaragua) (fig. 9)
.
Gen. Nov. 1
Figure 9. Head of Gen. nov. 1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
7(6).
.
. 		Anterior border of head generally straight, without secondary tubercles, with or without a central concavity (fig. 1) (Mexico to South America)
.
Passalus
(Pertinax)
 

7'.
.
.

Anterior border of head with 1 or 2 secondary tubercles (figs. 10, 11) or, if without tubercles, then horn “broken”, with vertical base then bent forward abruptly (fig. 12)
.

. .
8
Figure 1. Head of Passalus
(Pertinax) sp.
.
.
Figure 10. Head of Passalus (Mitrorhinus) lunaris
.
.
.
Figure 11.Head of Passalus (Passalus) interstitialis “Neleus” group
.
.
Figure 12. Horn of Passalus (Passalus) plicatus ("Neleus" group) – lateral view. Anterior at left
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8(7).
. 		Anterior border of head with a single, medial, secondary tubercle (fig. 10) (South America)
Passalus (Mitrorhinus)
 

8'.
.
.

 Anterior border of head with 2 partially or completely separated secondary tubercles (fig 11) (Arizona to South America, Antilles)
Passalus (Passalus)
9
Figure 10. Head of Passalus (Mitrorhinus) lunaris
Figure 11. Head of Passalus (Passalus) interstitialis “Neleus” group
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

9(8). .
.

Secondary tubercles contiguous at base (fig. 13)
10
.
 
9'.
. 		Secondary tubercles more or less separated (fig. 11) (Arizona to South America)
Passalus (Passalus) “Neleus” group
Figure 11. Passalus (Passalus) interstitialis “Neleus” group
Figure 13. Passalus (Passalus) jansoni “Phoroneus” group
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
10(9).
. 		Apex of central tubercle (horn) of MFS not free or almost not free (fig. 13) (Guatemala to South America)
Passalus (Passalus) “Phoroneus” group
 

10'.
.

 Apex of horn very free; horn with vertical base, then curves forward horizontally (fig. 14) (South America)
Passalus (Passalus) “Petrejus” group
Figure 13. Passalus (Passalus) jansoni “Phoroneus” group
Figure 14. Passalus (Passalus) plicatus “Petrejus” group
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11(1).
.
.
.
. 		Anterior margin of labrum deeply concave, with a “scooped out” excavation in labrum behind concavity of margin (fig. 15). Frontoclypeal suture absent (weak in Verres n. sp.). Antenna with short lamellae (fig. 16) (Mexico to South America)

.
.
.
.
Verres
 

11'.
.
.

Anterior margin of labrum straight, slightly concave, or convex (figs. 20, 21); if strongly concave, then frontoclypeal suture present
.
.
12
Figure 15. Verres hageni
Figure 16. Antenna of Verres hageni
Figure 20. Undulifer incisus
Figure 21. Vindex sculptilis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12(11).
.
.
.
. 		Anterior border of clypeus strongly convex in center. Frontoclypeal suture triarcuate and prolonged laterally toward supraocular ridge. Frontal ridges absent (fig. 20). Meso- and metasternon pubescent. Body length approximately 30mm (Mexico)


.
. .
.
Undulifer

Figure 20. Head of Undulifer incisus

12'.
.
.
.
.

Anterior border of clypeus slightly convex in center or with an obvious triangular protusion. Frontoclypeal suture not triarcuate, usually more or less straight. Frontal ridges present or absent. Meso- and metasternon pubescent or not. Body length variable

.
.
.
.
13
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
13(12).
.
. 		Internal tubercles of head extend anteriorly more or less the same distance as the external tubercles (fig. 21, 22), projecting beyond frontoclypeal suture when it is present
.
.
14
 

13'.
.
.

 Internal tubercles of head absent or, if present, not extending anteriorly to the level of the external tubercles (fig. 23), not projecting beyond frontoclypeal suture when it is present
.
.
15

Figure 21. Head of Vindex sculptilis
Figure 22. Head of Pseudacanthus subopacus
Figure 23. Head of Spurius bicornis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14(13).
.
.
. 		Apex of horn not free, clypeus vertical or almost vertical (45 degrees). Body usually flattened; length 20-30mm (fig. 21). (Mexico to Honduras and El Salvador)
.
.
.
Vindex
 

14'.
.
.

 Apex of horn free, clypeus usually horizontal. Body rounded; length 23-46mm (fig. 22 ). (Mexico to Guatemala)
.
.
Pseudacanthus

Figure 21. Vindex sculptilis
Figure 22. Pseudacanthus subopacus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
15(13).
. 		Center of face flat, without central horn, only a tubercle on each side. Body length 17-23mm (fig. 23)
.
Spurius

Figure 23. Spurius bicornis

15'.
.

Center of face with protuberances or horn. Body length variable
.
16
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
16(15).
.
.
Body length more than 51mm. Frontoclypeal suture absent. Anterior border of clypeus thin. Antennal lamellae very wide and curved (fig. 17). Elytra rounded. Wings and eyes reduced
.
.
Proculus
 

16'.
.
.
.
..

Body length less than 51mm (if longer, then frontoclypeal suture present, but if poorly defined then antennal lamellae short [fig. 16]). Frontoclypeal suture present or absent. Anterior border of clypeus thin or thick. Antennal lamellae, elytra, wings and eyes variable
.
.
.
.
17
Figure 16. Antenna of Verres hageni
Figure 17. Antenna of Proculus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
17(16).
.
.
. 		Frons partially or entirely rugose, frontoclypeal suture extends along frontal ridges, frontal ridges present from their junction to internal tubercles (fig. 26). Humeral angles square. Eyes usually not reduced

.
.
.
Chondrocephalus


Figure 26. Chondrocephalus purulensis

17'.
.
.
.
.

Frons smooth (if rugose, then frontal ridges absent between internal tubercles and hypothetical ridge juncture point). Frontoclypeal suture straight or slightly curved, not extending along frontal ridges. Humeral angles of elytra rounded and eyes reduced
.

.
. .
18
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
18(17).
. 		Frontoclypeal suture poorly defined or absent. Anterior margin of clypeus thin. Antennal lamellae short (fig. 16)
.
19

Figure 16. Antenna of Verres hageni

18'.
.
.
.
.

Frontoclypeal suture visible (if not visible, then wings reduced and humeral angles of elytra rounded and eyes reduced, but without setae or with scarce setae on anterior corners of metasternon and laterl groove of metasternon narrow). Anterior margin of clypeus usually thick. Antennal lamellae short or long
.
.
.
.
21
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
19(18).
.
.
.
. 		Body length >38 mm, if less, then anterior border of pronotum bisinuate (fig. 24), marginal groove of pronotum laterally and anteriorly wide and deep or narrow and shallow and lateral fossae of pronotum poorly or well marked (Veracruz to South America)

.
.
Veturius
20
 

19'.
.
.
.
.
.
.
.

Body length <39 mm.  Anterior border of pronotum more or less straight (fig. 26).  Marginal groove of pronotum laterally narrow and shallow.  Lateral fossae of pronotum well marked.  A. granulipennis with opaque elytra covered with small tubercles.  A. agassizi with slight longitudinal ridge between juncture of frontal ridges and anterior border of head (Chiapas to Costa Rica)
.
.
.
.
.
.
.
Arrox
Figure 24. Head of Veturius
.
Figure 26.:  Head of Arrox agassizi
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

20(19).
.
.

 Anterior border of pronotum more or less straight (fig. 25).  Marginal groove of pronotum laterally narrow and shallow.  Lateral fossae of pronotum well marked

.
V. (Publius)
 

20'.

.

Anterior border of pronotum bisinuate (fig. 24).  Marginal groove of pronotum laterally and anteriorly wide and deep.  Lateral fossae of pronotum poorly marked

Veturius (other subgenera)

Figure 24.  Head of  Veturius sinuatus

Figure 25.  Head of  Veturius (Publius) talamancensis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

21(18).
.
.
.

Antennal lamellae curved (if straight, then with large horn, frontal ridges absent, clypeus inclined 45 degrees; lateral metasternal groove glabrous and narrow; body length 25-45 mm [(fig. 27]) (Chiapas to Nicaragua)
..

.
Ogyges


Figure 27. Ogyges championi

21'.

Antennal lamellae straight
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
22(21).
.
.
 MFS with lateral ridges (fig. 28), if absent, then body length <26mm, mid-clypeus not swollen and from Panama or Colombia; MFS usually with large horn with apex free
. .
.
24
Figure 28. Head of Oileus sargi

22'.
.
.
.

MFS without lateral ridges (fig. 29, 30), if present, then anterior labral border deeply indented (fig. 31) (Odontotaenius cerastes); mid-clypeus often swollen; MFS with or without large horn with free apex
..

.
23
image not
available

 Figure 29. Head of
Odontotaenius
striatopunctatus

Figure 30. Head of  
Odontotaenius
yucatanus

Figure 31. Labrum of  Odontotaenius
cerastes
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
23(22).
.
.
.
 Antennal lamellae short, proximal lamella shorter than second lamella; movable spur of mesotibia reachs farther than distal end of second tarsomere; head with or without internal tubercles (figs. 29, 30)
.
.
.
Odontotaenius

 Figure 29. Head of
Odontotaenius
striatopunctatus

Figure 30. Head of  
Odontotaenius
yucatanus

23'.
.
.
.
.
..
..

Antennal lamellae long, proximal lamella equal to, or longer than, second lamella, if shorter, then elytra with striae absent or very weak and body length >40mm; movable spur of mesotibia not reaching past, or just reaching, distal end of second tarsomere, if surpasses, then clypeus and fronto-clypeal suture V shaped and from Mexico (Oileus bifidus); head without internal tubercles
.
..
..
.
.
.
Oileus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
24(22).
. 		Depressed area lateral and posterior to MFS with many hairs
.
25
 

24'.
.

 Depressed area lateral and posterior to MFS with few or no hairs
.
26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25(24).
.
. . 		Distal meso and meta tibia with all terminal spines pointed (fig. 32), body length 21-33mm (figs. 34,35) (Mexico to Colombia and Venezuela)

..

Heliscus

Figure 32. Distal mesotibia of Heliscus tropicus

Figure 34. Head of  Heliscus eclipticus

Figure 35. Head of  Heliscus ridiculus

25'.
.

 Distal meso and meta tibia with at least one terminal spine truncate (fig. 33, 36 ) (Panama to South America)

Figure 33. Distal metatibia and
tarsus of Popilius gibbosus

Figure 36. Head of  Popilius
tetraphyllus
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

26(24).
.
.
.

 Clypeus at least partially rugose with granulations.  Eyes reduced.  Humeral angles of elytra rounded; elytra with  punctures moderately defined.   Body length 25-32 mm (fig. 23) (Guatemala, El Salvador, Honduras)
.
.
.
Gen. Nov. 2
Figure 23. Head of Gen. nov. 2

26'.
.
. .

Clypeus smooth.   Eyes normal or reduced.   Humeral angles of elytra normal or rounded, (if rounded, then elytra usually with coarse  punctures).  Body length variable

.
27
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
27(26).
.
.
 Elytra with strong punctures, occasionally with many fine hairs laterally, humeral angles rounded.  Eyes reduced.  Frontal ridges and internal tubercles present
.
.
28
 

26'.
.
.
.

Elytra with weak punctures, laterally lacking fine hairs or, if hairs present, then only on humeral angles, humeral angles rounded or not.  Eyes reduced or normal.  Frontal ridges and internal tubercles present or absent
.
.
.
29
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
28(27).
.
.
Elytral punctures rectangular; interstriae narrower than striae; humeral angles glabrous.  Body length less than 31 mm (fig. 37) (Chiapas to Honduras)
.

Xylopassaloides
 

28'.
.
.
.

Elytral punctures circular; interstriae wider than striae; humeral angles, and usually sides, with dense, long hair; body length more than 24 mm (fig. 38) (north of Isthmus of Tehuantepec)

.
.
.
Proculejus
Figure 37. Head of
Xylopassaloides schusteri
Figure 38. Head of
Proculejus brevis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

29(27).
.
.
.

 Frontoclypeal suture absent, MFS without lateral ridges and tubercles, body length >24mm, movable mesotibial spur does not extend beyond end of second tarsomere (fig. 39) (Costa Rica, Panama?)
.
.

Pseudoarrox

Fig. 39:  Head of Pseudoarrox karreni

29'.
.
.
.
.
.
.

 Frontoclypeal suture almost always present; MFS almost always with lateral ridges and tubercles; movable mesotibial spur length variable; if frontoclypeal suture absent, MFS without lateral ridges and tubercles and mesotibial spur does not extend beyond end of second tarsomere, then body length <24mm and from Colombia and Ecuador (Petrejoides caldasi)
.
..
.
.

.
30
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30(29).
.
.
. 		Movable mesotibial spur extends beyond end of second tarsomere, if not, from Colombia; lateral pronotal groove width not varying; dorsal mesotibial ridge length >50% length of tibia  (fig. 40) (Mexico to Ecuador)
.
.
.
Petrejoides
 

30'.
.
.
.



Movable mesotibial spur does not extend beyond end of second tarsomere; lateral pronotal groove wider (and usually deeper) anteriorly than posteriorly (except in Y laticornis); dorsal mesotibial ridge length <50% length of tibia (except in Y. laticornis) (fig. 41) (Mexico north of the Isthmus of Tehuantepec)


.
.
.
Yumtaax
Figure 40. Head of Petrejoides sp.
Figure 41. Head of Yumtaax mazatecus