Miscellaneous. 331 



F.R.S., &c., in which that eminent scientist gives an interpretation, 

 differing from his own, of the statosphere tendrils which form the 

 characteristic feature of the new genus of freshwater sponges to 

 whicli Mr. Carter's name had been attached in recognition of his 

 very distinguished services. He wished to consider the subject 

 entirely apart from its personal relation to themselves, and only 

 as it concerned the stability of a genus, in which, as he claimed, 

 for the first time in the history of freshwater sjionges, these 

 tendrils had been noticed as distinctive features. 



He then, at some length, gave his reasons why we should not 

 ac30])t Mr. Carter's theory of the parasitic nature of these tendrils 

 or tiLunents, saying that of the two points in the paper most 

 likely to impress a student who had not seen specimens of the 

 genus referred to, or one unfamiliar with the general subject, the 

 first was founded upon certain appearances represented in figure 2 

 of Mr. Carter's plate. This figure shows an " axial canal" through 

 the centre of the filament, widening into the " tubular prolongation 

 from the process of the chitinous coat " of the statosphere and 

 representing the supposable digestive tract of the animal parasite. 



As after repeated and very careful examination of numer us 

 specimens, both in a fresh condition and after being subjected to 

 different methods of preparation, he had failed entirely to meet 

 with an instance showing similar appearances, he referred speci- 

 mens of all three species of the genus to Prof. Jos. Leidy, whose 

 fame as an accurate observer is world-wide ; to Mr. Juo. A. Ryder, 

 and to Prof. Kellicott and Mr. Henry Mills of Buffalo, the discoverers 

 of one of the above species. The efforts of these gentlemen were 

 equally unsuccessful, their ojjinion being well expi'essed in Prof. 

 Leidy's words, " In my mind there can be no question as to the 

 tendrils being part of the structure of the statoblast ; and their 

 parasitic nature would never have occurred to me." " The tendrils 

 are homogeneous extensions of the inner capsule of the statoblast ; 

 and I see no trace of the appearance to which you refer in Carter's 

 figure 2." A paragraph from the letter of Prof. Kellicott makes a 

 further point. These processes " are not found on the statoblasts 

 of any other species in the Niagara river ; I have examined hun- 

 dreds of the statoblasts of CartereUa tuhispenna, and have not found 

 one without said tube. I brought some of these, having wintered in 

 the river, to my room last May ; after a few days, there was sponge- 

 growth ; so this form, if a pai'asite, did not destroy the life, &c." 



The second point made by Mr. Carter was that the species 

 marked C. tuhiaperma from Buffalo was identical, as shown by its 

 spiculation, with one marked JJcteromet/enia ripens horn Lehigh Gap, 

 Pa. That one of these identical species should exhibit the tubular 

 prolongation and accompanying tendrils, while the other did not, 

 was considered presumptive evidence that the former was affected 

 in some abnormal way. To this Mr. Potts answered, that while 

 there was unquestionably much similarity in shape of the birotulate 

 spicules of the two sponges, covering the " seed-bodies " in the 

 ordinary fashion as a second or outer coat, the Lehigh-Gap species 

 alone exhibited the second class of long birotulatcs, interspersed 



