Genera Priotyrannus and Cacosceles. 375 
The other three agree with the figure and description which 
Thomson has given of the species. 
Thomson and Lacordaire must have either overlooked or 
misunderstood White’s description of the mandibles, for no 
mention is made by them of the difference in form. 
The first form is well shown in the figure given by Thom- 
son (Arch. Entom. i. pl. x. fig. 1) and is fully described in 
Lacordaire’s characterization of the genus. 
The second form fully resembles that of the female, but is 
somewhat larger in size. 
The female of the species was unknown to ‘Thomson and 
Lacordaire, while White’s reference to it is both inaccurate 
and incomplete. The following are its characters, taken from 
some fine specimens from the Animallai Hills :— 
Mandibles broader than thick, narrowed to an edge on the 
inner side, provided with teeth along their whole inner edge, 
strongly curved in and terminating in a sharp point at tip, 
meeting along their whole length when closed. Head and 
prothorax coarsely rugosely punctured as in the male; the 
lateral spines of the prothorax exactly as in the male, but 
with the spine at the anterior angle somewhat feebler. 
(White’s description in this respect is quite misleading.) 
Elytra as in the male. Antenne much slenderer than in the 
male, not surpassing three fourths the length ot the elytra, 
with the first six joits smooth, glossy, and sparingly punc- 
tured, the remaining joints dull and marked with fine longi- 
tudinal striations. ‘The last ventral segment of the abdomen 
is slightly elongated and is rounded at the apex. (In the 
male this segment is much shorter and broader and is nar- 
rowly and sinuately truncated at the apex.) 
In addition to the four specimens mentioned there is in the 
Museum collection a very small male from Bombay with 
mandibles of the female torm. It is much darker in colour, 
nearly black, but does not otherwise seem distinct. I have 
not seen any specimens of this genus with distinctly inter- 
mediate forms of mandibles. 
On extending my observations to allied genera I found a 
variation of precisely the same character in the African genus 
Cacosceles, as exemplified by some specimens of C. Lacor- 
dairet, Bates. Here were males with the female forms of the 
mandibles and males with intermediate forms. This was the 
more interesting as Lacordaire had, apparently with great 
confidence, described as females some of the intermediate male 
forms. The female is in fact very different from the male *. 
* For excellent figures of both sexes and descriptions of the females see 
Peringuey, Trans. 8. African Phil. Soc. iii. p. 145, pl. iv. figs. 1-4. 
These descriptions had escaped my attention before writing the above. 
