go Records of the Indian Museum. [Vor Lie 
(see p. 97 antea), and they were growing in very different types of 
environment, though in the same lake at a distance of less than 
five miles apart. The sponges from sta. 2I were living in most 
unfavourable conditions on the lower surface of blocks of clay part- 
ly embedded in soft mud, which permeated their whole substance, 
and in a situation liable to desiccation with a change of wind, and 
also to the effects of nightly frost. Those from sta. 20 on the other 
hand were living in much deeper water, protected from frost and 
wind and not in any danger of being choked by mud (v. p. 91). The 
sponges from the blocks of clay were in a somewhat similar situa- 
tion to those of the var. syriaca I collected in the Lake of Tiberias,! 
except that the latter were attached to solid stone. In the other 
instance the method of growth is similar to that of Spongilla fragilis 
in Japan.* 
The specimens from the edge of the Persian lake are so en- 
veloped in and permeated by mud that their whole structure is dis- 
torted, whereas those of the Lake of Tiberias were normal in struc- 
ture but small. Moreover, there is no trace of green corpuscles in 
the Persian specimens, though minute extracellular algae of various 
kinds are found in their parenchyma. 
The specimens from both types of environment in the Hamun- 
i-Helmand were in an active vegetative condition in December, 
~but both contained numerous gemmules. I can find no trace of 
embryos. 
No specimens of EF. fluviatilis from the Hamun bear any particu- 
lar resemblance to those of the same species described from lakes in 
Central Asia by Weltner (0p. cit.), except that the skeleton-spicules 
of those growing on reeds have a somewhat similar outline to 
those from Issyk Kul figured by him in figs. 8-14 on p. 65 of the 
work cited. In the occurrence in the sponges from the margin of 
the lake of occasional abnormally large birotulate spicules they 
resemble the Australian E. multiformis,? but that species (? or 
variety of EF. miillert) possesses bubble-cells in its parenchyma. I 
have examined a cotype or schizotype sent me before the war by 
Dr. Weltner and have found in it a spicule of this type, but neither 
in Persian nor in Australian specimens have I discovered such 
spicules 7m situ on the gemmule. I see no reason to regard them 
as adventitious but believe that they are produced free in the paren- 
chyma, perhaps as a result of abnormal environment. 
HYDROZOA. 
Hydra vulgaris, Pallas. 
1911. Hydra vulgaris, Annandale, Faun. Brit. Ind., Freshw. Sponges, etc., 
p. 148, fig. 29, p. 131, fig. 27A. 
! Annandale, Fourn, As. Soc. Bengal (n.s.) 1X, p. 59 (1913) and XI. p. 455 
(1916). 
2 Annandale and Kawamura, YFourn. Coll. Sci. Univ. Tokyo XXXIX, p. 13 
(1916). 
8 Weltner in Michaelsen and Hartmeyer’s Faun. Siidw. Australiens III, 
p- 138 (1910). 
