1918.] F. H. Gravely : Passalidae of the World, 43 



Proculus goryi (Melly). 



Passalus gonji, Mellv, 1833, pi. lvi. 



Two specimens from Vera Paz, Guatemala, 67-72 mm. in length. 

 Proculus goryi may readily be distinguished from the other two species before me by 

 the obsolete upper tooth of the mandibles, normally flattened mentum, and glossy elytra. 



Proculus opacipennis (Thomson). 

 Passalus opacipennis, Thomson, 1857, pp. 420-421, pi. xxi, fig. 4. 



Three specimens from Ecuador and two from Guatemala, 51-56 mm. in length. 

 Proculus opacipennis has a long and slightly curved upper tooth on each mandible, 

 a normally flattened mentum, and matt elytra. 



Proculus mniszechi, Kaup, 1868. 



Proculus mniszechi, Kaup, 1868&, pp. 11-13. 



Eight specimens from Guatemala (mostly from Vera Paz), one from Ecuador, and one 

 from San Pedro Sula, Honduras. They vary from 53-69 mm. in length. 



Proculus mniszechi has an acute and well developed upper tooth on each mandible, glossy 

 elytra, and a mentum with the inner margin of the forwardly directed lateral processes 

 turned almost at right angles to the rest of the plate in a ventral direction to form a pair 

 of smoothly rounded lobes. 



Subfamily PASSALINAE. 



The subfamily Passalinae as represented in the collection before me includes five 

 clearly defined genera, and a large assemblage of species separated from one another by 

 various combinations and modifications of characters so graded as thoroughly to obscure 

 their true relationships one to another. 



In the first three genera the clypeus is always exposed and the antennae always 

 have three lamellae. The first of them, Chondrocephalus, only differs from the primitive- 

 Pseudacanthine genus Popilius in having ^no suture between the clypeus and the frons 

 and no hair on the lateral areas of the metasternum. C. quinquecomutus is to some 

 extent transitional between the two genera, having definite traces of the suture ; but as 

 these are not very distinct and as the lateral areas of the metasternum are hairless it 

 seems to me to make, on the whole, a better Chondrocevhalus than Popilius. 



The second genus, Vindex, contains one species, V. agnoscendus, in which the 

 clypeo -frontal suture is distinct throughout as in the Pseudacanthinae ; and but for its 

 flattened form and separate elytra with hairless sides this species might have been held to 

 indicate the relationship of its genus to Proculejus instead of to Chondrocephalus ; for 

 Vindex possesses the main peculiarities of the dentition characteristic of Proculejus 

 (see above, p. 10). 



One species of Vindex, described below for the first time, has the elytra united as 

 they are in the next genus Proculejoides. But whereas this species retains the flattened 

 form characteristic of other species of Vindex, Proculejoides has assumed the more massive 

 form ordinarily assumed by flightless species of all groups. 



g2 



