170 Records of the Indian Museum. [Vol,. X, 



muscular and runs forward. There appear to be two uteri and 

 ovarian tubes. 



The ventral pore is small, i"275 mm. from the head. lyateral 

 lines were not distinguished. A nerve ring was also not seen. 



This specimen agrees with Oxysoma falcatum, v. Linst. {14a) 

 from the intestine of Geoemyda (Nicoria) trijuga, Schweigg. in size, 



general shape, structure of head, proportion ff • , and pro- 

 portion ^-"^^^y^- It differs from, it in possessing a striated cuticle 

 and in the proportion p?!^^^?'!!^^ ,^,hich is ' instead of ~ as 

 in 0. falcatum. 



3 Heterakis macronis, n. sp. 



(PI. xix, figs. 17-24. PL XX, figs. 25-34.) 



Seven specimens, four males and three females, were found in 

 the intestine of Macrones aor, Ham. Buch., obtained from the 

 market, Lucknow. They are delicate hair-like animals. Their 

 absolute and relative measurements are given in table III, page 186. 

 The greatest diameter of the body is situated at the posterior end 

 of the oesophagus, and the breadth of the body diminishes rapidly 

 toward the head, gradually toward the tail. In the majority of 

 fixed specimens^ the anterior end of the body is curved toward the 

 dorsum. The tail of the male curves toward the ventral sur- 

 face. 



The head (figs. 17, 18 and 19) is rounded and very slighth^ 

 greater in diameter than that part of the body which immediately 

 succeeds it. There are no lips (figs, 18 and 19). The mouth is 

 formed by a shallow funnel-shaped depression in the anterior end 

 of the oesophagus, and is surrounded by a ring of slightly thickened 

 cuticle. This ring is somewhat thicker in the ventral than in 

 the dorsal segment; the anterior end of the oesophagus is also 

 slighth^ more prominent in the ventral than in the dorsal segment, 

 consequently the transverse plane of the mouth is tilted very 

 slightly toward the dorsum. Viewed in the sagittal plane (fig. 17), 

 the same cuticular ring is visible, and it can be seen that it is 

 carried outward in the two midlateral lines to form ribs, which 

 support the commencement of the lateral membranes. Cephalic 

 papillae, if present, are very sm.all and do not raise the cuticle. 



The lateral membranes (figs, 17 and 24-34) extend from the 

 head to a level shortly in front of the anus. At the head they are 

 supported by sickle-shaped thickenings of their outer and anterior 

 margins. They increase rapidly in breadth to a maximum of 

 •048 mm. at the level of the end of the oesophagus. At this level 

 the breadth of each membrane is equal approximately to half the 

 diameter of the body. At a distance of "56 mm. from the head a 

 ti read-like process of protoplasm passes outward from the lateral 

 line in the substance of the lateral membrane to the outer mar- 

 gin of the latter structure (fig. 24). This is doubtless a sense 

 organ. 



