Polyzoa Entoprocta and Ctenostomata. 
33 
cases; the length and greatest diameter of the largest zooecia are 2 55 and 0 272 mm. 
In a colony from the neighbourhood of Calcutta the largest zooecia are, however, 
only i'6i5 long by 0 221 in diameter, while in one from Port Canning, some 30 miles 
distant, the measurements are 0 935 and 0153. These differences appear to be con- 
siderable if individual colonies are compared, but they disappear completely in along 
series of specimens. 
In all my Siamese specimens the ectocyst is rather thick and has a slight yellow- 
ish tinge. The parietal muscles, though well developed in some zooecia, are not 
invariably stronger or more numerous than in specimens from India or Egypt. In 
some Siamese zooecia, however, they extend further up the zooecia than is usual in 
Indian examples. 
Family HISLOPIIDAE. 
1911. Hislopiidae, Annandale, Faun. Brit. Ind., Freshw. Sponges, etc., p. 199. 
igii. Hislopiidae, id., Rec. Ind. Mus. VI, p. 199. 
Genus Hislopia, Carter. 
I have now been able to examine ample material of all the forms hitherto des- 
cribed in this genus with the exception of H. placoides (Korotneff), and on my recent 
tour was fortunate in discovering a new species which, owing to the transparency of 
its ectocyst, the study of the anatomy was peculiarly easy. The following key to the 
species may, therefore, be of some value : — 
I. Orifice armed with four very long spines .. ... H . placoides . 
II. Orifice unarmed or bearing four short spines. 
A. Zooecia in uncongested parts of the colony almost 
circular, slightly truncated proximally and dis- 
tally. Ectocyst yellowish, orifice quadrate or 
subquadrate, usually with four short spines . . H. moniliformis. 
B . Zooecia in uncongested parts of colony oval or ovoid . 
i. Ectocyst perfectly hyaline and colourless; 
terminal zooecia assuming a fan-like out- 
line before becoming oval; no orificial 
spines. 
ii. Ectocyst yellowish; terminal zooecia not 
passing through a fan-shaped stage. 
a. Zooecia (at any rate in peripherial 
parts of the colony) constricted 
and produced at the proximal end ; 
the margins not noticeably thick- 
ened ; orifice as a rule without spines 
b. Zooecia not or very rarely peduncu- 
late ; their margins thickened and 
chitinized; four short orificial 
spines frequently present 
H. malayensis. 
H. cambodgiensis. 
H. lacustris. 
