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



Each duct opens into ati excretory vesicle (PI. xxvi, lig. i. and 

 PI. xxviii, 7 ex. ves.), a large spherical space situated amongst 

 the yolk glands, i to i"2 mm. distant from the anterior extremity. 

 The wall of the vesicle is composed of fine fibrous tissue and the 

 vesicle opens on the dorsal surface by a fine pore (PI. xxviii, 

 fig 7 ex.p.). 



Summary of the Literature concerning the Genus Polystomum. 



Seven species of Polvstoma are known at the present day, 

 viz : — 



(i) Polvstoniuni integerritnuni, Rud. in Rana temporaria, url- 

 nary bladder. 



(2) Polystomum ocellatum, Rud. in Emys lutraria, Bp., fauces. 



(3) Polystomum. ohlongum, Wright, i888, in Sternothaerus 

 odoratus, Gray, urinary bladder. 



(4) Polystomum coronatuni, I^eidy, 1888, in Cistudo Carolina, 

 Gray, nares, phar3^nx. 



(5) Polystomum hassalli, Goto, 1900^ in Kinosternon penn- 

 sylvannicum^ urinary bladder. 



(6) Polystomum sp. {=P- ohlongum, Leidy 1888, not P. 

 ohlongum, Wright, 1884) Goto 1900, in Pseudemys rugosa, urinary 

 bladder. 



(7) Polystomum kachugae , sp. nov., in Kachuga lineata (Gray), 

 urinary bladder. 



Comparison of species. 



(r) Polystomum integerrimum, Rud. (lyiterature Nos. i, 2, 

 3, 4, 6, 7, 8, 9, II, 12, 16, 17, 18 19, 20^ 21, 22, 23, 24, 26, 27, 28). 



This species is distinguished from the other members of the 

 genus by the branched character of the intestinal rami, the bran- 

 ches anastomosing across the midline ; in the remaining species 

 the two rami do not give off branches. 



(2) Polystomum ocellatum, Rud, (Literature Nos. 5, 7, 16, 

 20, 22, 24). 



vSummary of No. 24 Lit. v Willemoes Suhm. — Zeitsch. f. 

 Wissensch. Zool., vol. 22, pp. 29 — 39, that portion which deals 

 with the anatomy of Polystomum ocellatum. The author's des- 

 cription is based on the work of von Siebold (20a). " Der Schild- 

 krotenschmarotzer ist im ausgedehnten Zustande i| Linien lang, ^ 



Linie breit In seiner Korperform ahnelt er durchaus dem 



Polystoma der Frosche .... Am vorderen Leibesende zwischen 

 Pharynx und Geschlechtsoffnung bemerkt mann jederseits eine 

 warzenformige Hervorragung .... ich beobachtete sie jedesmal, 

 sowie dass das Thier sie willkiirlich aus — und einziehen konne . . . 



Was die Napfe der Haftscheibe betrifft, so weichen sie 



won denen des P. integerrimum dadurch ab, dass sie von einem 

 festen Ringe, wahrscheinlich chitiniger Substanz umgeben sind, 



der in f elder abgetheilt ist, deren jedes 2-3 Locher zeigt 



Zwischen den beiden untersten (Saugnapfen) finden sich zwei 

 grossere, mit den spitzen nach unten stehende, von einander 



