236 Records cf the Indian Museum. [Vou Sey ida 
described from Mesopotamia and occurs fossil in Great Britain. 
Shells from the springs are smaller and rather thinner than usual 
and perhaps a little broader in proportion to their height, but 
specimens from larger bodies of water exhibit great individual 
variation in these respects, merging gradually into the thick narrow 
form called C. cor by many conchologists. 
The molluscs of the springs, therefore, may be said to show 
very little response to their environment in structure. 
Insecta. Insect life, even in the middle of winter, is by no 
means deficient in the springs. The most abundant and the most 
commonly observed species was the mosquito,' Theobaldta longi- 
areolata, the larva of which was found in water so saline as to be 
almost undrinkable, as well as in the excellent spring at Hurmuk, 
claimed locally to contain the finest water in all Iran. Both 
larvae and pupae were seen in December and imagines were 
observed hatching out. The latter, which were common also at 
Nasratabad, were, however, very sluggish at this season and made 
no attempt to suck blood. 
Small Rhynchota of the family Corixidae were frequently 
noted in the springs and in that at Hurmuk two species of 
Micronecta (M.desertana and M. biskrensts) were abundant. The 
former has been described by Mr. Distant as a new species, while 
the latter was described by Horvath from the oasis of Biskra in 
the Algerian desert. 
Small Hydrophilid and Dytiscid beetles are not uncommon, 
and a large species of the latter family was captured in the spring 
at Hurmuk. 
CRUSTACEA. ‘The only Crustacea seen in the springs were 
Ostracods, which often swarmed on the bottom. In asample from 
an artificial tank containing water pumped from a spring in the 
Baluch desert Mr. Gurney found tests of Cyprinotus incongruens 
and flyocypris bradyi, both widely distributed species. 
HIRUDINEA, So far as I can judge, oniy one species of leech 
(Limnatts nilotica) occurs in the springs. It is common in all those 
at which transport animals are watered and is dangerous both to 
men and animals owing to its habit of entering their mouths while 
they are drinking and sticking to the tongue or pharyngeal wall. 
THE FAUNA OF STAGNANT - POOLS: 
Under this heading I propose to consider pools connected 
neither with water-courses nor with small desert springs. Such 
pools are found occasionally in depressions, probably always of 
artificial origin, in Seistan and apparently owe their water to 
percolation. ‘The largest pool of the kind we saw was at the village 
of Daulatabad towards the south of the country. It formed a 
fairly large village pond and lay at the base of a low ridge of stiff 
! For the identification of this mosquito and of the other Nemocera mentioned 
in this paper | have to thank Mr. Edwards of the British Museum. 
