280 



Memoirs of the Indian Museum. 



[Vol. VIT, 



can writers, the walls between the pits doubtless forming the "network of ridges" 

 referred to by von Linstow. 



This species is readily distinguished from P. serpentulus by the absence of cepha- 

 lic alae, and by the simple character of the spicules and the presence of an accessory 

 piece in the male. 



Porrocaecum pristis, sp. nov. 



(Figs. 13-15O 

 Host: Saw- fish (Pristis perotteti). Position: intestine. Locality: Ulubaria, R. 

 Hughli. 



The male measures up to 26*6 mm. in length and 074 mm. in thickness; the 

 female 34*2 mm. and 1*06 mm. respectively. The diameter of the head is o*i6-o*i8 

 mm. The cuticle has transverse striations 87-10/* apart. The lips (fig. 13) are 

 small, and pass into the neck without any constriction at their bases. Each has a 



narrow, bilobed, anterior process, carry- 

 ing two small cuticular projections on its 

 inner surface. The dorsal lip is shorter 

 than the ventro-lateral lips, and has two 

 large papillae. Each ventro-lateral lip 

 has one large, lozenge-shaped ventral 

 papilla and a much smaller lateral pa- 

 pilla, situated a little more anteriorly. 

 Dentigerous ridges are present, at least 

 on the anterior processes of the lips. 

 The teeth are very small. Interlabia are 

 absent. The oesophagus has a straight 

 posterior glandular portion, or ventricul- 

 ous, of oblong shape. The distance from 

 the head end to the posterior end of the 

 ventriculus is 23-27 mm. The ventri- 

 culus is o*6 mm. long in the male, 

 075-078 mm. in the female. The anterior caecal prolongation of the intestine 

 measures 0*95-1 3 mm. in length. There is a pair of prominent, rounded, cervical 

 papillae at o*65-0'67 mm. from the anterior end. The nerve-ring is situated at 

 o*46-o - 53 mm. from the same point. The excretory system terminates, as usual in 

 the genus, in a long unicellular gland with a very narrow duct leading to the excre- 

 tory pore, which is situated just between and behind the ventro-lateral lips. 



The tail of the male (figs. 14, 15) is conical, slightly curved ventrally, and 

 measures 0*38 mm. in length. There are slight caudal alae, and most of the papillae 

 have rather long, rib-like pulps. There are about 40 pairs of preanal papillae, and 

 in addition to these there is one median sessile papilla on the anterior lip of the 

 cloaca. One pair of papillae, apparently belonging to the preanal series, is situated 

 just at the corners of the cloacal opening. There are seven pairs of postanal papil- 



la-/ ;rt7?2/. 

 Fig. 13. — Porrocaecum pristis. 

 dorsal view. 



Head of female 



d.i., dorsal lip ; p. . right papilla of same. 



