OTIDOCEPHALUS.—OOPTERINUS. 267 
One specimen. This curious little species seems to be a near ally of the similarly- 
coloured Brazilian O. rujicollis, Chevr. (1=0. bicolor, Rosensk.), which is described as 
having the prothorax tuberculate at the base and the rostrum straight and cylindrical, 
characters not applying to O. versicolor. In the latter the convex, coarsely punctured 
portion of the head is separated from the smoother, flattened, lateral portion by a sharp 
ridge, a peculiarity not mentioned in Chevrolat’s diagnosis of O. rujficollis. 
73. Otidocephalus bidentatus, sp.n. (Tab. XIII. figg. 30, 30a.) 
Moderately elongate, black, shining ; clothed with long, scattered, erect, blackish sete and intermixed, rather 
coarse, decumbent white hairs, the latter confined to the sides of the prothorax, and to the outer half and 
the apical declivity of the elytra, and arranged in an irregular double or treble row on the interstices 2, 4, 
6, 8, and in a single row on the others, the vestiture of the scutellum and under surface white, the legs 
with intermixed white and blackish hairs. Head very sparsely punctate, flattened above the eyes and 
obsoletely foveate between them, the latter moderately large and not very widely separated; rostrum 
considerably shorter than the prothorax, punctato-sulcate at the sides, smooth along the middle; antenne 
with joints 3-7 of the funiculus short, 2 a little longer than 3, the club ovate. Prothorax moderately long, 
cylindrical in front, and a little narrowed and constricted behind, somewhat closely pnnctate at the base 
and apex, the rest of the disc with a few widely scattered punctures only, the flanks smooth. Elytra 
very much wider than, and two and one-half times the length of, the prothorax, moderately convex, 
flattened on the disc anteriorly, very gradually widening to the middle, broadly subtruncate at the base, 
the humeri prominent; finely seriate-punctate, the interstices 1, 3, 5, 7,9 each with a single, and the 
others with an irregular double or treble, row of minute punctures. Femora each with two narrow 
parallel-sided teeth—the inner one long and obliquely truncated at the apex, the outer one shorter and 
narrower and also truncated. Anterior tibie strongly sinuate within, rounded externally in their 
basal half, 
Length 43, breadth 2 millim. (3?) 
Hab. Mexico (Flohr, in Mus. Berol.). 
A very remarkable species, differing from all others of the genus known to me in 
the bidentate femora. ‘The decumbent white hairs on the outer interstices of the 
elytra show a tendency to form small fascicles, but this may be due to abrasion. ‘The 
single example seen is contained in the Berlin Museum. 
OOPTERINUS. 
Oopterinus, Casey, Ann. N. York Acad. Sci. vi. p. 438 (1892). 
The type of this genus is Otidocephalus perforatus, Horn, of the United States. It 
includes the apterous Otidocephalids, with more or less connate, ovate elytra (the 
humeri being completely effaced and the base of the elytra very little wider than that of 
the prothorax), which are widest before the middle, the scutellum minute or invisible 
(as in Lemomerus, Kirsch), and the eyes coarsely facetted and well separated. The 
rostrum is depressed at the base above. The first two ventral segments are connate. 
The tarsal claws are feebly appendiculate. The males of some of the species have the 
first ventral segment depressed or sulcate down the middle. In 0. bactrianus the 
2MM 2 
