342 LAMELLICOENIA. 



which they much resemble, by the very different armature of the four hind tibise, which 

 have two spines or long teeth at the outer apex instead of one, and on the median ridge 

 a row of denticulations, ending sometimes with a short spine. In the var. copra the 

 spines and denticulations are much stronger than in the type. The size of P. valgus 

 typ. varies from 16 to 24 millim. 



ll. Phileurus quadrituberculatus. 



Scarabmus quadrituberculatus, Palisot de Beauv. Ins. Afr. et Amer. p. 42, t. 1 b. fig. 5. 

 Phileurus quadrituberculatus, Burm. Handb. der Ent. v. p. 162 \ 

 Phileurus bajulus, Perty, Del. Anim. Art. Bras. p. 44, t. 9. fig. 7 2 . 

 Phileurus cephalotes, Casteln. Hist. Nat. Ins. Col. ii. p. 116. 



Hab. Mexico 1 ; British Honduras, Belize (Blancaneaux) ; Honduras, Kuatan Island 

 (Gaumer) ; Nicaragua, Chontales (Belt, Janson). — South America to Brazil 12 . 



The four hinder tibise in this species have three strong teeth at their outer apex, and 

 a row of broad and strong denticulations on the median ridge. 



AMBLYODUS. 



Amblyodus, Westwood, Trans. Ent. Soc. Lond. 1878, p. 32. 



The following is the only known species of this genus, distinguished from Phileurus 

 chiefly by the tridentate mandibles. In this feature it agrees with Trioplus, to which 

 genus it is very closely allied, differing chiefly by the simple fore-tarsal claws in the 

 male and the entire apex of the clypeus. 



1. Amblyodus taurus. (Tab. XXI. fig. 2, s .) 



Amblyodus taurus, Westw. Trans. Ent. Soc. Lond. 1878, p. 32, t. 2. figg. 1 a-e \ 



Hab. Nicaragua, Chontales (Belt x ) ; Panama, Volcan de Chiriqui 2000 to 3000 feet 

 (Champion). 



Three examples, including the type-specimen of Westwood. 



The specimen described by Prof. Westwood has only two teeth on the right mandible, 

 but as the two other examples ( J $ ) have both mandibles tridentate, it appears probable 

 that the bidentate state in this case is an aberration. The female (recognizable, as usual 

 in the Dynastidee, by the entire apical margin of the apical ventral segment) is precisely 

 similar to the male, except that the cephalic horns are very much shorter, and the 

 declivous anterior surface of the thorax is only half as large. I suspect, however, that 

 the difference is not always so great, as the females in Trioplus are almost exactly 

 similar to the well-developed males, whilst minor males have much shorter cephalic 

 horns. 



