404 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 37. 



Genus TROCHOSPONGILLA Vejdovsky. 



TROCHOSPONGILLA LEIDYI (Bowerbank). 



Spongilla leidyi Bowerbank, Proc. Zool. Soc. London, 1863, p. 445. 

 Meyenia leidyi Potts, Monogr., p. 212, pi. 5, fig. 3; pi. 10, fig. 1. 



In a recent note ^ I referred my Trochospongilla pliillottiana to 

 the synonymy of this species, being of the opinion that I had found 

 intermediate forms. I have now no doubt, however, that in this 

 behef I was wrong, and that both the Indian species of TrocJio- 



spongilla (T. latouchiana and T. pliillot- 

 tiana) are in reahty distinct both from T. 

 leidyi and from one another. They often 

 grow in close association, and microscopic 

 preparations of the one are therefore hable 

 to contain spicules of the other. Were it 

 possible to unite them, it would be neces- 

 sary to include T. leidyi also. 



Genus HETEROMEYENIA Potts. 



The species of the ''genus" Carterius 

 should, in my opinion, be distributed be- 

 tween tliis genus and Ephydatia. To Hete- 

 romeyenia I would assign Mills' Carterius 

 tuhisperrna and C. stepanowii (Dybowski), 

 while Potts' C. latitenta and C. tenosperma 

 should, if my views are correct, be relegated 

 to Ephydatia. The one distinctive charac- 

 ter of Carterius is the fact that the aperture 

 of the gemmule is jjrovided with highly 

 developed filaments or processes, which, 

 however, differ greatly in the different spe- 

 cies. This is undoubtedly a specific char- 

 acter of importance, but it would be more 

 convenient to base the generic diagnoses 

 of the Spongillinse (the genera of which, it 

 nnist be admittetl in view of the connecting 

 links that occur, are largely artificial) on 

 the nature of the gemmule spicules — a 

 coiu'se to which tlu^ <^>iily objection that can be urged is that in some 

 forms the gemmules are unknown. There can be little doubt, how- 

 ever, that in many such cases gemmules will be found when speci- 

 mens in the fully mature condition are examined ; while the right of 

 certain other forms (as for instance, those genera characteristic of 

 Lake Baikal) to occupy a position in the subfamily is more than 

 doubtful. 



Fig. 2.— Skeleton and gemmule 

 spicules of tubella pennsyl- 

 vanica from s. india, x 240. 



» Records of the Indian Museum, vol. 3, p. 103. 



