310 Memoirs of the Indian Museum. [Vol. VIT, 



anterior region of the body, that belonging to the anterior uterus being confined to this region, while 

 the posterior ovary eventually runs back to terminate in the hinder region. Ova usually large and 

 thick-shelled, of oval shape, and laid at different stages of development in different species. 



Hab. Intestine of Chelonia and freshwater fishes. 



Genotype : F. faleata (v. Linst., 1900), from Geoemyda irijuga. 



Owing to the great similarity in structure between most of the species of Falcau- 

 stra, specific determination depends very largely upon measurements. The following 

 admittedly artificial attempt at a key to the species is based almost entirely on 

 male characters, and therefore omits one species (F. Jcachugae) of which only the 

 female is known. 



A. Inhabiting tortoises. 



I. Several preanal sucker-like organs present in male. 



a. Pairs of caudal papillae io; spicules about 0*9 mm. 



long . . . . . . . . siamensis. 



b. Pairs of caudal papillae 11 ; spicules about 1*3 mm. 



long . . . . . . . . lambdiensis. 



II. Preanal sucker-like organs absent. 



a. Pairs of caudal papillae 10 . . . . faleata. 



b. Pairs of caudal papillae 11 . . . . testudinis. 



c. Pairs of caudal papillae 16-18 . . . . steivarti. 



B. Inhabiting fishes. 



I. A preanal sucker-like organ present in male. Head wider 



than neck . . . . . . . . barbi. 



II. Preanal sucker-like organ absent. Head narrower than 



neck . . . . . . . . leptocephala. 



Genus Zanclophorus, nov. 

 The collection contains two interesting species which are clearly very closely 

 related to Falcaustra, but differ from it, in our opinion, sufficiently to necessitate the 

 formation of a new genus, which may be defined as follows : — 



Kathlanidae : closely resembling Falcaustra in general appearance. Head somewhat narrower than 

 neck, surrounded by a slight cuticular collar at the base. Three large, flattened lips, each carrying a 

 pair of rather prominent papillae, and bordered internall}' by cuticular fringes. A long and wide buccal 

 cavity present, with a cuticular lining. In place of the continuous cuticular ring which surrounds the 

 buccal cavity in Falcaustra , there are three separate cuticular supports, in the form of double horse- 

 shoes, at the corners of the mouth. There is no distinct pharynx, but the structure of the oesophagus 

 is otherwise the same as in Falcaustra, and it is coloured in the same way with reddish pigment, of which 

 there is a special mass in the neighbourhood of the nerve-ring. Bulb pear-shaped, with narrow middle 

 region. Cervical papillae small and sessile, some distance behind the nerve-ring. Excretory pore 

 towards hinder end of oesophagus. Caudal end of male without alae, but with a single, well-developed, 

 muscular, preanal sucker (not a mere fan-like arrangement of muscles). Spicules similar to those of 

 Falcaustra, but relatively much longer. A large, but not completely chitinized, accessory piece 

 present. Female genital organs as in Falcaustra. 



Hab. Stomach and intestine of Chelonia. 



Genotype : Z. annandalei, sp. nov.. from Testudo travancorica . 



