MEGAPENTHES.— PHYSOEHINUS. 385 



The coxal plates extend rather broadly to the outer margin of the body, and are very 

 little widened inwards. Dr. Candeze is of opinion that the insect cannot be satisfac- 

 torily separated from Megapenthes. 



Group PHYSORHINI. 



PHYSORHINUS. 



Physorhinus, Eschscholtz, in Silberra. Rev. Ent. iv. table (1836) ; Candeze, Monogr. Elat. ii. p. 387., 

 t. 3. fig. 7. 



Of the fourteen described Physorhini (two of which are here treated as varieties of 

 P. distigma), five inhabit Central America *, whence three others are now added ; 

 Anchastus frontalis, Horn f , from New Mexico, also belongs to it. Physorhinus is 

 confined to the New World, and it is one of the most characteristic genera of Elateridae 

 in Tropical America. It has the posterior coxal plates enormously developed, the 

 subtriangularly dilated median portion being nearly or quite as wide as the first ventral 

 segment. The sutures between the prosternum and propleuree are widely separated for 

 the greater part of their length, rather abruptly converging behind, and channelled 

 in front. The middle coxse are deeply excavate externally for the reception of the 

 base of the middle femora, the upper portion forming a broad plate. The third 

 joint of the antennae is very short. The third joint of the tarsi is strongly lamellate, 

 the fourth joint small. The curious pallid coloration of the whole or part of the head is 

 common to all the species, many of which have spotted elytra. The maculation of the 

 elytra shows very little sign of variation, except in P. erythrocejphalus and P. distigma; 

 the latter is a common Central-American species, and also varies enormously in size. 



These insects are chiefly found in forest-clearings, by beating the branches of fallen 

 trees. 



The Central- American species may be identified by the annexed table : — 



a. Hind angles of the prothorax bicarinate. 

 a' '. Apical margins of the elytra denticulate. 

 a". Elytra obsoletely striate. 



a'". Elytra each with two large flavous spots on the disc — one before, 



the other beyond the middle erythrocephalus. 



b"'. Elytra each with a flavous or reddish spot or streak towards the 

 apex, sometimes extending forwards along the outer part of the 

 disc to the base, and sometimes obsolete distigma. 



* Physorhinus galapagoensis, Cand. (nee Waterh.), presumably from the Galapagos Islands, is stated by 

 Candeze (Monogr. Elat. ii. p. 395) to occur on the corresponding coast of Colombia and also in Guatemala. 

 Further evidence is required before it can be admitted into our list. The insect in question, if the specimen 

 in the British Museum is correctly named (which I believe to be the case, as it agrees with the description), 

 cannot possibly be retained in Physorhinus, it having the sutures between the prosternum and propleurse 

 formed as in Anchastus, i. e. narrowly separated throughout. 



f The name frontalis being preoccupied in the genus, it is here changed, at the author's request, to fusculus. 



biol. centr.-amek., Coleopt., Vol. III. Pt. 1, October 1895. 3 D 



