260 _ HETEROMERA. 
as far as the coxe; penultimate joint of the four anterior tarsi dilated, excavate; hind tibie without 
oblique ridges on their outer face (the short subapical one excepted); body very broad, short; the form 
of the claws and other characters as in Mordella. 
This new genus is proposed for a single species from Mexico. It is one of the most 
interesting forms of Mordellide yet discovered, differing as it does from all other 
members of the group Mordellides in the shape of the last dorsal segment and in that 
of the metasternum. 
1. Cothurus iridescens. (Tab. XI. figg. 7; 7a, maxillary palpus.) 
Very broad, short, metallic blue, the prothorax in front and the head with brassy reflections; the elytra densely 
and coarsely, the prothorax more finely, punctured; the elytra, scutellum, disc of the prothorax, and the 
head in the middle sparsely blackish-brown-pubescent, the sides of the head and of the prothorax more 
densely clothed with whitish pubescence, the head golden-pubescent in front. Head exceedingly broad, 
short; the eyes very large, extending to the occiput, and thickly pubescent; the oral organs (the tip of 
the mandibles excepted) flavo-testaceous; antenne flavo-testaceous, the outer four or five joints infuscate, 
slender, rather short, joints 3-5 thin, equal in length, 5 a little wider than 4, 6-10 serrate, 8-10 about 
as broad as long; prothorax strongly transverse, deeply sinuate on either side of the broad median basal 
lobe, the latter subtruncate ; elytra convex, a little narrower than the prothorax, short, only about one 
and a half times as long as broad, broadly and separately rounded at the apex; the last four dorsal and 
ventral segments fulvous, thickly clothed with fulvous-golden-pubescence, the rest of the under surface 
obscure violaceous and yellowish-cinereous-pubescent; anterior and intermediate legs in great part and 
the hind tibial spurs testaceous; the hind femora, tibiw, and tarsi black, the base of each tarsal joint 
sometimes paler; the inner spur of the hind tibise very elongate, three times as long as the outer one. 
Length to end of the elytra 3-3}, breadth 1-2 millim. 
Hab. Mxxico, Cordova (Sallé). 
Five examples. In some of these specimens the anterior tibie are more strongly 
bowed inwards than in others; the former, no doubt, are males. All have the palpi, 
antenne, and pygidium similarly formed. Labelled Mordella iridescens, Chevr., in the 
Sallé collection. 
TOMOXTA. 
Tomoxia, Costa, Fauna Regn. Napol., Col. Eter. Mord. p. 8 (1854); Lacordaire, Gen. Col. 
v. p. 609. 
Four species are here referred tc this genus: two of these agree exactly in their 
general structure with the European type of the genus; the other two differ in having 
the scutellum less transverse, the middle tibiee a little longer (not, however, exceeding 
the entire tarsus in Jength), the penultimate joints of the anterior and middle tarsi 
feebly dilated, and the last joint of the maxillary palpi not so stout. The North- 
American 7. bidentata (Say) has the penultimate joints of the anterior and middle 
tarsi broader, and the eyes not extended to the occiput or lateral margin. In the 
European 7’. biguttata the eyes are hairy; but in 7. didentata and the species here 
described they are apparently bare. 
