94 Records of the Indian Museum. [Vor. XVIII, 
been observed, but they are highly developed and specialized in 
the species to be described here. Some species of the genus 
bear a close external resemblance to those of the group of Pluma- 
tellae that has been named Alcyonella, but in Alcyonella a horny 
ectocyst is present as well as the gummy substance by means of 
which the zooecia are agglutinated together. In preserved speci- 
mens of Hyalinella the ectocyst is apt to shrink and lose its gela- 
tinous character, butin the natural condition its structure and 
appearance are most characteristic. It is usually much harder 
than the zooecium of the Lophopodinae. Six species may now be 
assigned to the subgenus:—Plumatella punctata, Hancock, the 
type-species; P. bigemmis, sp. nov.; P. indica, and P. longigemmis 
(Annandale); P. jheringi (Meissner), and P. lendenfeldi (Ridley). 
The first of these is widely distributed in Europe and North America 
and occurs also in tropical Africa and in India; the second is here 
described from E. Persia; P. indica and P. longigemmas are Indian ; 
P, jheringi comes from Brazil, and P. lendenfeldz from Australia. 
These species may be distinguished by the following key :— 
I. Ectocyst not greatly swollen, fairly soft, not concealing 
the identity of the zooecia. 
A. Statoblasts of one type only, all free. 
1. Statoblasts not much longer than broad, very 
variable — 3 ... P. punctata. 
2. Statoblasts nearly 1} times as long as broad, 
not particularly variable... .. P. longigemmis. 
B. Fixed statoblasts present as well as free .. BP. bigemmis. 
II. Ectocyst stiff, not greatly swollen but compacting the 
zooecia together into a solid mass. 
Statoblasts oval, rounded at the ends we De dndica. 
III. Ectocyst very copious, soft; the distinction between zooe- 
cia entirely obliterated. 
A. Statoblasts oval, subtruncate at the ends ... H. lendenfeldt. 
B. Statoblasts subcircular or polygonal ... HA. pheringt. 
As is shown in this key the distinction between my Australella 
and Jullien’s Hyalinella is merely a matter of degree. Some speci- 
mens of the species now to be described might be assigned with 
equal propriety to either. Nor does the one differential character, 
considered in this light, seem sufficient for generic separation from 
Plumatella. 
Plumatella (Hyalinella) bigemmis, sp. nov. 
The zoaria grow prone on the stems of plants and have 
much the appearance of those of H. punctata, except that the 
ectocyst is still more transparent and swollen and quite smooth 
on the external surface. Young zoaria have an almost linear 
growth, slightly zig-zag owing to the subterminal buds being 
produced on opposite sides of alternate zooecia. Though these buds 
are lateral in origin they are directed almost straight ahead, so 
that the deviation from a straight line is not great. As the colony 
develops, the zooecia are pressed together into a compact layer. 
This is brought about by the production of lateral branches which 
form an acute angle with the main axis of the colony. A radiating 
