128 



Mr. H. J. Carter on the 



thus alters considerably its general appearance externally as 

 well as the structure internally. Lastly, the colour under 

 drying, as before stated, may fade in part or altogether. Still 

 there are some things in a sponge which are seen better when 

 dry than when fresh. 



Such difficulties beset no other classification in natural 

 history. But what is to be expected otherwise, when, in 

 addition to this, the protean character of the sponge, whose 

 transformations are endless in the soft parts, and only ap- 

 proached in number by being stereotyped in ihe harder ones, 

 is considered ? Hence the unsatisfactory and indefinite cha- 

 racters, especially of the families, which will be found in the 

 following classification. 



Class SPONGIDA, Huxley. 



Order I. CARNOSA. 

 Without evident skeleton*. 



Order II. CERATINA. 



Fio-. 1. 



Fibre of Ceratiua : a, horny fibre ; b, core ; c, transverse section of fibre, 

 showing concentric laminar structure around the core ; d, bud of fibre. 



Possessing a skeleton composed of horny fibre with a granu- 

 lar, chiefly hollow, core, containing for the most part no foreign 

 bodies. 



* Here and henceforth it should be remembered that the diagnoses 

 respectively refer to the general characters. And as regards priority iu 

 my Classification, it must be considered quite empirical. But that fibre- 

 less spiculeless sponges might pass by gradation into fibrous spiculous 

 ones I have no other grounds to go upon. 



