Report on а Collection of Sponges from the Volga River. 
В у 
P. D R E 2 V О J. 
(Zoolog. Museum of the Russian Academy of Science, Leningrad.) 
(With 2 fig.) 
The present note contains the working up of material on freshwa- 
ter sponges collected by Dr. A. L. Behning in different localities of the 
lower part of the Volga during the study of övergrowth on the under- 
water parts of vessels and other buildings. There are 5 species recorded, 
the chiel interest of them is the occurence of S. carteri at Astrakhan. 
All the 7 specimens of this species present thin crusts with а 
pavernent layer oi gemmules. Our specimens differ in some respects 
irom the Indian typical form, ln typical cases the gemmules are disper- 
sed in the parenchyma and do not present а compact pavernent layer. 
Yet more important is the construction of the macrocsleres. Our speci¬ 
mens bear very short points; sometimes the points of the spicules are 
almost rounded;, you seldom encounter points of middle length. In typi¬ 
cal cases the points are long. 
I have already recorded the occurence of S. carteri in Turkestan, 
at Bukhara and B$yram-Ali. Specimens from the latter place have the 
same tendency, only more feebly expressed, to shorten the length of the 
spicule’s points and to round them. Out of the Volga delta I have 
already described а form, Spongilla rotundacuta, which I have considered 
as а separat species closely related to S. carteri. Its macroscleres, with 
rounded points, are cylindrical. After the Undings at Bayram-Ali and 
especially at Astrakhan, which connect this form with typical S. carteri, 
it will be more correct to consider it not as on separate species, but 
as а variety of S. carteri—var. rotundacuta. 
