470 SEEEICOKNIA. 



are small in the form gemmiferus. The antennae are considerably dilated and extend 

 very little beyond the hind angles of the thorax in the males, shorter in the females ; 

 the third joint is not much longer than the second. Some of the specimens in the 

 Janson collection have the thorax opaque. P. ornamentum seems to be restricted 

 to the central plateau of Mexico. 



11. Pyrophorus OCCidentalis. (Tab. XX. figg. 28, 6 ; 28 a, genitalia, 6 .) 



Elongate, rather narrow, the females a little broader, moderately convex, shining, fusco-cinereo-pubescent; 

 pitchy-brown or brown, the prothorax with a large, oval, oblique, slightly raised, yellow vesicle on either 

 side behind, this extending to the lateral margin and almost to the base, the propleurae with a corresponding 

 yellow patch. Head closely, coarsely punctate, broadly depressed in the middle in front, the eyes large 

 and rather prominent; antennae stout, serrate, extending very little beyond the hind angles of the 

 prothorax in the male, shorter in the female, the third joint slightly longer than the second. Prothorax 

 as long as broad, rather convex, flattened or depressed on either side of the middle of the disc ; the sides 

 moderately rounded, slightly constricted behind and converging in front; the hind angles long and 

 divergent, without distinct carina ; the surface densely, moderately coarsely punctate, the punctuation a 

 little more scattered on the middle of the disc, down the centre of which is a smooth line ; the base with 

 a prominent laterally compressed tubercle in the centre. Elytra two and one-half times the length of the 

 prothorax, slightly rounded at the sides, narrowing from about the middle ; finely or somewhat coarsely 

 punctate-stria te, the interstices flat or feebly convex, and densely, rugulosely punctate ; the apices 

 conjointly rounded, the sutural angles sharp. Beneath closely and finely, the presternum coarsely 

 and sparsely, punctate ; mesosternum with the sides of the cavity slightly raised behind. 



Length 17-18|, breadth 5-5| millim. ( d 1 $ •) 



Hob. Mexico, Tres Marias Is. (Forrer), Acapulco (Edge). 



Six specimens, three from each locality, varying very little in size. Closely allied to 

 P. ornamentum, but differing from it in the less elongate thoracic tubercle (this being 

 abruptly raised in front) and the relatively shorter elytra. The thoracic vesicles are 

 very large and raised. The genitalia of the males are very differently formed from 

 those of any of the allied species. P. occidentals appears to be confined to the Pacific 

 coast of Mexico and the adjacent Tres Marias Islands. 



12. Pyrophorus mexicanus. (Tab. XX. fig. 29, genitalia, 6 .) 



Elongate, rather narrow, the females broader, moderately convex, shining, fusco- or fusco-cinereo-pubescent ; 

 piceous, pitchy-brown, or brown ; the prothorax with a moderately large, ovate, oblique yellow vesicle on 

 either side behind, this being placed near the lateral marginfand in some specimens extending to near 

 the base ; the propleurae with a large yellow patch behind ; the legs and antennas brown or ferruginous. 

 Head closely, coarsely punctate, broadly depressed in the middle in front; the eyes large, rather 

 prominent in the male ; antennae moderately stout, serrate, extending to considerably beyond the hind 

 angles of the prothorax in the male, and scarcely reaching these angles in the female, the third joint a 

 good deal longer than the second. Prothorax as long as or a little longer than broad, feebly convex, and 

 flattened or depressed on either side of the middle of the disc in the male, convex and shorter in the 

 female ; the sides converging in front and feebly rounded in the male, strongly rounded in the female ; 

 the hind angles long and divergent, carinate ; the surface closely, moderately coarsely punctate, the punc- 

 tuation becoming a little more scattered on the middle of the disc, down the centre of which is a smooth 

 median line, this being impressed towards the base in some specimens ; the base with a small laterally 

 compressed tubercle in the centre in the male, and a larger and more prominent longitudinal elevation in 

 the female. Elytra about two and two-thirds longer than the prothorax, gradually narrowing from about 



