444 



MISS A. M. EVANS ON THE STRUCTURE AND OCCURRENCE 



In the Carabid, Nebria brevicollis (text-fig. 10), the larval hypopharynx (h.) 

 is produced at the corners into two prominent lobes (m.) identical in position 

 with the maxillulse of Pterostichus. Apparently they are homologous with 

 these appendages. Each measured '09 mm. in width, and the combined 

 width of maxillulsa and hypopharynx was - 6 mm. No distinct suture 

 separating the maxillula from the hypopharynx could be detected. The 

 maxillulre here were more prominent than in the larvse of Pterostichus and 

 Carabus violaceus which were examined. 



In various larval Elateridas the hypopharynx was examined and great 

 uniformity of construction was found to exist. 



The condition seen in Campylus linearis will serve to illustrate the type. 

 The hypopharynx (text-fig. 11), which is of stiff chitin, is supported by a 



Text-fis-.ll. 



Text-fig. 12. 



Campylus linearis. Labium and 

 hypopharynx, dorsal aspect. 

 X 90. h. Hypopharynx. 

 /. Labium, m. Maxillula. 



Anatis ocellata. Labium and hypopharynx, 

 dorsal aspect. X 55. a. Anterior skeletal 

 system, h. Hypopharynx. l.p. Labial palp. 

 m. Maxillula. p. Posterior skeletal system. 



stronger transverse chitinous plate. Its anterior border is independent of the 

 underlying surface of the labium. It bears a pair of triangular plates (m.), 

 measuring at the base '05 mm. These I regard as vestigial maxillulse from 

 considerations based on a comparison with those of Pterostichus. The com- 

 bined width of the hypopharynx and maxillulse is '24 mm. Each of the 

 latter carries long, fine hairs which are mingled with similar but shorter 

 hairs borne by the labium and by the basal portions of the maxillae. 



The larva of r Telephorus lituratus is described by Miss 0. M . Payne (38). 

 From pi. 2. figs. 14, 15, in which the hypopharynx is shown, it seemed that 

 this structure was very similar to that of Elateridas. Examination of the 

 mouth-parts of a specimen confirmed this supposition. I discovered hidden 



