530 REVISION OF THE AMYCTERID^, 



forming in its deepest portion a well defined pit, the preanal 

 fossa; the posterior edge is sinuous, and is produced back 

 between the blades of the forceps. The fascicles vary in size and 

 exact position, but are situated on or near the edge of the excava- 

 tion. The forceps consist of two blades projecting posteriorly; 

 they are concave on their inner faces, from which spring the 

 blade-like laminae; these latter and the forceps vary greatly in 

 size. On dissection the inner ends of the forceps are seen to lie 

 in a groove on either side of a projection corresponding to the 

 preanal fossa; to this is attached a median, vertical, chitinous 

 plate, the ends of the forceps being united to this by muscles; 

 also to this plate there is attached a slender curved rotl situated 

 asymmetrically on the right side. The penis is hard and 

 chitinous, and varies in the shape of its free extremity. The 

 last two dorsal segments in the male are hard and chitinous; the 

 apical tergite is the longer, is narrowed at the apex, and is 

 overlapped by the broader subapical segment. In the female (as 

 in all Amycteridce) only the last dorsal segment is chitinous. 



In the measurements the lengths have been taken from the 

 apex of the rostrum to the apices of the elytra, but, owing to the 

 great convexity of these insects, the total length so taken is 

 often less than the combined lengths of head, prothorax, and 

 elytra. The position in which the head has been set also 

 influences the measurement; while many species present consider- 

 able variation in size. 



Table of the Species. 

 Group. 



i. 1(12). ^ with a strong gular horn. 



2 (9). Elytral interstices seriate, granulate, none of the interstices 



costiform. 



3 (8). Prothorax closely set with small, round granules. 



4 (5). Elytral sculpture irregular, excepting third and fifth interstices, 



fourth interstice not continued to base. P. mirabilis Kirby. 



5 (4). Elytral sculpture regular, all interstices reaching base. 



6 (7). Size moderate, prothoracic granules finer than in P. mirabilis. 



P. ritfolineata Maeleay. 



7 (6). Size large, prothoracic granules not finer than in P. mirabilis. 



P. CoxiM&e\. 



