390 Mr. H. J. Carter on the (Jirrous Appcmlages 



XLI. — Form and Nature of the Cirrous Appendages on 

 the Statohlast oi Carterella latitenta, Pt)/(!«, cDc, originallif 

 designated " Spongiophaga Pottsi." By H. J. Carter, 

 F.R.S. &c. 



[Plate XIV.] 



ITp to the time of my publishing all that I could learn 

 from Mr. Potts's " slides " respecting the cirrous appendages 

 of the statohlast in that species of Spongilla which, in 

 kind compliment to myself, he had named " Carterella 

 tenosperma " (for which appendages I proposed the name 

 " Sjyongiophaga Pottsiy\ to commemorate his interesting dis- 

 covery), 1 could come to no other conclusion than that they 

 Avere so closely allied to those filaments in some of the marine 

 sponges for which 1 had proposed the name " Spjongiophaga 

 comnnmis,^'' that they might justly claim the same generic 

 appellation (' Annals,' 1881, vol. viii. p. 354, pi. xvii.). But 

 natural history is progressive (that is, evolutionary), like every 

 other kind of human knowledge, wliich, on the other hand, is 

 so entirely based on assumption, that one feels asliamed of the 

 least precipitancy, and never safe except under the most 

 modest utterance. Yet tiiere are perplexing questions in 

 which we are apt to forget this, and so rush at the merest 

 shadow of assistance to help us out of our ditficulties. From 

 such arose my proposing the generic name '' S2)07igio])haga " 

 for the cirrous appendages on the statoblast of Carterella 

 tenosperma — since, although the former is as abundant, com- 

 mon, and evident to our senses, in the Hircineai, as the grass 

 of the field, no one yet has been able to find out (with all our 

 knowledge of creation) what it is or where it came from ; but 

 Mr. Potts's discovery of the cirrous appendages among the 

 Spongillina, where they had never been known or even sus- 

 pected to exist before, and their great' resemblance to the fila- 

 ments of Spongiophaga communis ^ led me to hope that a step 

 towards the solution of this question had at last been attained ; 

 and thus originated the name " Hpongiophaga Pottsi.'''' De- 

 sirable, however, as it may be to find out any thing that will 

 throw some light on the nature of Sp)ongiophaga communis^ it 

 now appears to me that we cannot hope tbr much in this 

 respect from the cirrous appendages of the statoblast ; for in a 

 specimen of Carterella latitenta lately received from ]\Ir. Potts 

 their form is so different and so much more indicative of their 

 real nature that, whatever their office may be, their presence 



