332 



Memoirs of the Indian Museum. 



[Vol. VII, 



will readily show. There is no appreciable difference in the structure of the mouth- 

 parts, upon which it is usual to base new genera in this family. 



The figure of D. willeyi is given in order to show the rudimentary " leaf-crown," 

 or corona radiata, surrounding the entrance to the buccal capsule. The presence of 



c.r. 



Fig. 66.—Diaphanocephalus willeyi. Head of female; lateral view. 

 c.r . corona radiata ; d., duct of dorsal oesophageal gland ; s., wall of buccal capsule (optical 



section). 



this structure in a member of the genus Diaphanocephalus indicates a close proximity 

 to the members of the subfamily Strongylinae. 



The genus Diaphanocephalus is here referred tentatively to Railliet's subfamily 

 Deletrocephalinae, which, if we exclude the members of Skrjabin's genus Kiluluma, 

 would appear to constitute a natural group. 



Diaphanocephalus minutus, sp. nov. 



(Figs. 67-69.) 



Host: Cobra (Naja tripudians). 



This is the smallest species so far encountered in this genus. The males measure 

 from 4*9 to 5"0 mm. in length and o - 2 mm. in thickness ; the females from 5*1 mm. to 

 5-3 mm. and 0*21 mm. respectively. The dorso-ventral diameter of the head is 015 

 to o*i6 mm. The head is laterally compressed. There is a distinct constriction behind 

 it. The mouth is furnished with three pairs of small papillae which are actually the 

 terminations of the three pairs of longitudinal parenchymatous bands characteristic 

 of the genus. These bands are lateral and spring from a collar which surrounds the 

 base of the buccal capsule. The collar is in the form of a horseshoe with the open 

 ends coming practically into apposition in the dorsal middle line. The buccal capsule 

 is about 0*2 mm. deep and is thick- walled. When viewed in optical section in the 



