332 Records of the Indian Museum. [Vo.. XI, 
Breadth of last segment, °25 mm. 
Length of last segment, I mm. 
Length of neck, ‘25 mm. 
The head consists of four sessile, crimpled bothridia, which 
have their edges slightly thickened. There is no myzorhynchus, 
and accessory suckers are absent. 
There is a short neck. The worms consist of 5, or at most 
6 segments. In many, what appeared to be the terminal vesicle 
was still intact. As in Shipley’s specimens (Ceylon Pearl Oyster 
Reports, V, London, 1906, p. 53) the genital organs were 
developed in the very first segment, and no short, shallow, young 
proglottides were observed in any of our specimens. The genital 
aperture was only obvious in the last segment. This segment had 
the sides slightly curved, and the greatest breadth was across the 
middle, through the genital aperture. 
The testes are very numerous and large, and were disposed on 
each side of the longitudinal axis of the proglottid. The cirrus 
pouch is not conspicuous. No spines were observed on the penis. 
The deferent canal runs transversely to the genital pore. The 
vitteline glands were disposed parallel, and external to the testes. 
The ovary and shell gland were situated posteriorly. The ducts 
from the vitteline glands also unite in the centre line posteriorly. 
The oviduct occupies a central position and runs anteriorly in a 
loosely coiled manner. 
The genus Phyllobothrium, Van Beneden, is closely related to 
the genus Cvrossobothrium, Linton. The latter differs from the 
former only in having the bothria pedicelled and in possessing no 
neck. It will be noted that our specimens do not possess acces- 
sory suckers. No mention is made of accessory suckers in Phyllo- 
bothrium blaket, Shipley and Hornell (Ceylon Pearl Oyster Reports, V, 
London, 1906, p. 70, figs. 72 and 73), although suckers are shown in 
P. pammicrum, Shipley and Hornell. Johnstone was unable to find 
accessory suckers in specimens of P. lactuca, Van Beneden (Tvans 
Biol. Soc. Liverpool, XX, 1906, pp. 159-160), and he refers to the 
absence of a myzorhynchus in both P. lactuca, Van Beneden, and 
P. thridax, Van Beneden. 
No myzorhynchus was observed in our specimens and no myzo- 
rhynchus is described or figured for the following species :— 
P. minutum, Shipley and Hornell, 
P. pammicrum, Shipley and Hornell, 
P. blakei, Shipley and Hornell, 
P. lactuca, Van Beneden, - 
P. thysanocephalum, Linton. 
A neck is absent in P. blaket, Shipley and Hornell, long in 
P. lactuca, Van Beneden, P. minutum, Shipley and Hornell, and 
P. thysanocephalum, Vinton. 
The characters of the genus Spongtobothrium, Linton, are as 
follows :— 
