438 



MISS A. M. EVANS ON THE STRUCTURE AND OCCURRENCE 



and Oummings (10). Enderlein (15) expressed the opinion that the "glands " 

 are appendages homologous with the maxillulse of Collembola, while 

 Bonier (4) calls them the " fulturre " or lingual stalks, and says that the 

 maxillse are represented by a pair of membranous lobes attached to the tongue. 

 The mouth-parts of British Psocidas are, owing to their minute size, 

 exceedingly difficult of dissection, but, through the kindness of Dr. Imms, 



Text-fig. 6, 



Large Psooid. Tongue, dorsal aspect. The plates m. and chitinous cord c.c. are seen 

 through the membranous dorsal surface of the hypopharynx and maxillula. X 2-50. 

 b. Brush-like sclerite. c.c. Chitinous cord = " duct." h. Hypopharynx. I. Lobe 

 of hypopharynx. m. Maxillular lobe of hypopharynx. p. Chitinous plate = " lingual 

 gland." o.s. (Esophageal sclerite. s.m. Sclerite rising from apex of plate (p.) and 

 associated with m. t. Tendon. 



I have been able to examine specimens of a very large species which is a 

 native of India. The hypopharynx, whose walls are of very delicate mem- 

 brane, is figured (text-fig. 6) from the dorsal surface. The ventral wall is 

 thickened laterally to form the paired, convex, sole-shaped plates of yellow 

 chitin (p.) (seen by transparency), the so-called " lingual glands." The size 

 of the specimens made it possible to dissect out the hypopharynx and open up 



