Malacoderm Genera Prionocerus and Idgia. 329 
2. Prionocerus bicolor. 
Prionocerus. bicolor, Redt. Reise der Novara, ii. p. 109, t. 4. fig. 3 
(1868) ; Gorh. Ann. Soc. Ent. Belg. xxxix. p. 318 (1895). 
Tdgia (Prionocerus) bicolor, var. notaticollis, Pic, L’Kchange, xxvi, 
p. 53 (1910). 
g. Anterior tarsi and genital armature (PI. XI. fig. 2) asin 
P. ceruleipennis, Perty; except that the median lobe is less 
sinuate at the tip. 
Hab. Invia, Sikkim, Allahabad ; Burma; Siam; Mata- 
YAN ReGron generally. 
This insect is extremely closely related to P. ceruleipennis, 
and occurs with it in some of the Malayan localities, 
differing from that species in having the antennz a little 
less dilated in the two sexes, and the elytra wholly fulvous. 
The type was from Java. P. bicolor has been found in 
numbers by Mr. H. Stevens at Gopaldhara, in the Rung- 
bong Valley, Sikkim, unaccompanied by its near ally. 
Females preponderate in the series before me. A varicty 
from Tharrawaddy, Burma, with the scutellum yellow has 
been recorded by Gorham (/. ¢.), and another, from Sumatra, 
with a dark median patch on the prothorax, by Pic. 
Ipeta. 
Idgia, Castelnau, in Silberm. Rev. Ent. iv. p. 27 (1836); Hist. Nat. 
Ins. Coleopt. i. p. 275 (1840). 
Deromma, Kollar and Redtenbacher, in Hiigel’s Kaschmir, iv. 2, 
p. 512 (1844). 
Diprosopus, Mulsant, Mém. Acad. Lyon, i. p. 209 (1851). 
Thaccona, Walker, Ann, & Mag. Nat. Hist. (8) ili. p. 260 (1859) ; 
Gemminger and Harold, Cat. Coleopt. vii. p. 2179 (1870) [sub 
Cedemeridee ]. ; 
The generic name Idgia, type I. terminata, Cast., from 
Senegal, is here used for all the Prionocerids with the 
antenne filiform or moderately serrate, at least in $9. The 
structure of the anterior tarsi is precisely similar to that of 
Prionocerus, and the form of the genital armature of the 
males also ‘shows their close relationship. ‘The superficial 
resemblance of many of the species to the (#demerid 
Nacerdes melanura, L., and the Telephorid Rhagonycha fulva, 
Scop. (=melanura, Oliv.), is very striking, one, indeed, 
having been described as belonging to the first-named group, 
The Museum material includes, in addition to species here 
enumerated, a very elongate, large, subopaque, blue form, 
