248 Mr. H. J. Carter on a Variety o/'Spongilla Meyeni. 



Ohs. This Spongilla chiefly differs from 8p. Meyeni of Bom- 

 bay in the decidedly spinous character of one-third of its largest 

 spicules, while about the same proportion in the Bombay spe- 

 cies can be only termed " incipiently spinous." The excess in 

 size of the elementary parts generally of the Bombay species 

 over those of the variety in the river Exe amounts to nothing, 

 specifically considered. 



But there is a much more decided difference between var. 

 Parjitti and the birotulate English species termed Sp.jiuviatilis^ 

 which also grows in the river Exe, inasmuch as the spicules 

 of the skeleton in the latter are all smooth, the shaft of the 

 birotules, somewhat constricted in the centre, approaching to 

 hour-glass shape, with the margin only of the rotules minutely 

 dentate, almost fringed*. 



I am indebted to my intelligent friend, the able naturalist of 

 Exeter, Mr. E. Parfitt, for having brought to my notice the 

 existence, in the river Exe, of the variety and species of 

 Spongilla above mentioned, where this gentleman found them 

 some time since ; and, he having kindly submitted them (in the 

 dry state, with his own notes of what they were when alive) 

 for my examination and publication, I cannot do better than 

 dedicate the variety to him. 



The indistinct colour of var. Parjitti may perhaps be attri- 

 buted to the filtering position in which it grows, viz. on the 

 beam of the weir over which the Exe falls at the Salmon-pool, 

 if not also the more spinous state of its spicules generally ; 

 while the position of Sj). fluviatilis^ taken from the Canal and 

 parts of the Exe just above, where Mr. Parfitt found it incrust- 

 ing the stems and leaves of Anacharis and on hard substances 

 respectively, presents not only the usual fawn-colour of Sponges 

 in general, but also a less spinous state of the spicules — per- 

 haps from a less agitated state of the water in which it 

 grows. 



I still adhere to the term '^ seed-like body," instead of 

 adopting that of " ovary," used by Dr. Bowerbank ; for where, 

 literally, we cannot yet make " head or tail " of an organism, 

 it certainly is premature to designate any part of it by a term 

 which is essentially connected with the true process of genera- 

 tion. Moreover I have already pointed out the identity in 

 structure and composition of the seed-like body of Sj>. Carteri 

 with the winter-egg of the Bryozoaf ; and I am pleased to 

 find just now, by chance, that Meyen, long before this, had 



* See also Dr. Bowerbank's figures and descriptions, Proc. Zool. Soc. 

 Lond. Nov. 24, 1863 ; and Ray Soc. publ. 

 t Annals, 1859, vol. iii. p. 331. 



