298 



Memoirs of the Indian Museum. 



[Vol. VII, 



lateral alae run down the body from a little in front of the nerve-ring nearly as far 

 as the tail. The oesophagus is muscular throughout, i '4— 1*48 mm. long in the male, 

 1 '5-1 '6 mm. in the female. It is divided a little behind the head into a very short 

 anterior portion, and a long posterior portion which ends in a well-developed pyriform 



bulb. At the division of these two portions 

 there appears to be some kind of valvular ap- 

 paratus. The bulb measures 0'25~0'26 mm. 

 in length and O'17-O'io, mm. in diameter 

 transversely, and contains the usual valves. 

 The nerve-ring is situated at 0'4~o - 46 mm., 

 and the excretory pore at o*6-0'65 mm., from 

 the anterior extremity. 



In the male, the tail (figs. 35, 36) which 

 is 0*38-0 '43 mm. long, is provided, for rather 

 less than the anterior half of its length, with 

 wide alar expansions, into which some of the 

 caudal papillae project. The remainder of the 

 tail is simple and slender, ending in a fine, 

 tapering point. There is a circular preanal 

 sucker, O'i2-0'i3 mm. in diameter, with well- 

 developed chitinous wall, situated at 0'i5-0'i7 

 mm. in front of the cloaca. The greatest 

 diameter (antero-posterior) of the opening of 

 the sucker is about 0^07 mm. The two 

 spicules are very unequal and dissimilar. The right spicule is slender and simple, 

 measuring 078 mm. in length. The left is provided with broad alae at the sides, has 

 a barbed tip, and is only 0*45 mm. long. There is no accessory piece. There are 

 twelve pairs of caudal papillae, the arrangement of which can be understood most 

 readily by reference to the figures. Three pairs, of which the middle pair is more 

 ventrally situated and slightly larger than the others, form a group just in front of the 

 filamentous portion of the tail. The fourth pair is solitary, projecting laterally into 

 the alae. There is an adanal cluster of papillae consisting of four more or less lateral 

 pairs with long stalks, and two small, sessile, ventral pairs, one in front of and one 

 behind the cloaca. Of the four lateral pairs the most posterior is the stoutest, and 

 projects laterally. The next is more ventrally directed. The next is again lateral ; 

 while the most anterior of the group projects ventrally. There are two very slender 

 and long-stalked papillae on either side of the sucker. 



In the female the tail is long and straight, tapering to a slender point. It 

 measures i*o-i'02 mm. At about the middle of its length there is a very minute 

 pair of caudal papillae. The vulva is situated behind the middle of the body, at 

 about 3 mm. from the posterior end. It leads into a vagina (fig. ^y) which is convoluted 

 in a characteristic manner — running forward at first, as a strongly muscular ovejector, 

 it curls first in a semicircle so as to return towards the body-wall on the ventral side. 



Fig. M.—Pseudaspidoderapavonis. Head of 

 female; lateral view. 



c, cordon ; c'.. optical section of same; d.i., 

 dorsal lip ; p., papilla. 



