258 



Mr. B. F. Cumminjjs on the 



literature of tliis p;ronp *. This sclerite (sometimes called 

 "lyriform orgiin " and homologized with the hypopharyiix) 

 and glands (better known as basal pieces), almost unique in 



Vis. 1. 



Infra-buccal plate of Polyplax brachyrhynehus (Anoplnra). The whole 

 of the top of the head has been dissected away, so that the plate is 

 seen from above. The bundle of elongated needle-like trophi, which 

 are sketched in only diagramniatically, have been drawn on one cide 

 to leave the plate clear. 



MO = Mouth-opening ; D = Rostral denticles; 8 = Infra-buccal plate 

 (or sclerite) ; C = Chitinous chords ; G= ? " Gland " (this was only 

 visible on one side). Greatest length of the plate = '01.3 of a milli- 

 metre ; oreatest width = 'OIG. 



the comparative anatomy of the insect-mouth, occur in their 

 typical form in the suborder Ischnocera of the Mallophaga 



* Vide V. L. Kellogg, Proc. Calif. Acad. Sci. vol. vi. 1896. R. Snod- 

 gra-ss, Trans. Am. Ent. Soc. xxxi. Nr. 4, 190o, pp. 297-307 ; P. Z. S. 191.3, 

 p. 128. Armenaute, Boll, della Soc. di Naturalisti in Napoli, xxiv. 

 (ser. 2, vol. iv.) 1910, p. 7G. 



