20 Mr. H. J. Carter on two new Species of Gumminese. 



fresh or in spirit it lias much the appearance of wet chamois- 

 leather ; and although not more than half as tough (for it can 

 be easily torn), it is so soft and resilient that it will receive the 

 impression of the nail, and efface the same of its own accord. 

 After it has been dried, however, it becomes hard like glue, 

 and breaks with a similar fracture; while, wet or dry, its aspect 

 is so homogeneous, that at first sight one would hardly conceive 

 it to possess all the structures above mentioned. 



The pores, the vents, and branched systems of excretory 

 canals, together with the siliceous spicules, all point to its inti- 

 mate connexion with the sponges ; while the entire absence of 

 the so-called sponge-fibre-structure, and the presence of the 

 ovoid cell (fig. 8, a), which makes up the greater part of the 

 body-mass, together with the remarkably granulated form of 

 the epithelial layer of cellules on the surface of the excretory 

 canals (fig. 15, a), are equally characteristic of the Gumminese. 



By the so-called " sponge-fibre-structure " I mean the ske- 

 leton of sponges, par excellence, which is horny in many, and 

 composed of spicules united together into a fibrous structure by 

 amorphous sarcode in others. " Fibre" is a bad name for this 

 structure ; for, besides being inappropriate, there is real fibre 

 (that is, minute linear filament) to be seen in many soft parts 

 of sponges, which has nothing to do with the skeleton what- 

 ever. Thus, although in the Gumminese, there is no " sponge- 

 skeleton-fibre " so to speak, the cuticula and a great part of 

 the body is made up of fine, intercrossing filaments, which are 

 so soft that, on drying, they all sink their form into a common 

 homogeneous mass, like hard glue. 



Nothing can be more unlike sponges in general than the 

 slippery, resilient, amorphous, rounded, sublobed, flat, incrust- 

 ing, homogeneous-looking mass presented by the Gumminese ; 

 while, perhaps, a piece of wet dough resembles them most. 



Although the vents appear to retain their circular form, the 

 pores are more like crevices — that is, linear, and sometimes tri- 

 angular like the form of a leech-bite (fig. 13), not circular, as 

 they are in the true sponges. This may be owing to the struc- 

 tural lining of the pore, which, together with that of the excre- 

 tory canals, as before stated, in the Gumminese consists of a 

 rough, granulated layer, each granule of which is a separate 

 cellule (fig. 9, b) (probably flagellate in the living state) ; while 

 in the true sponges the pore is circular and smooth, as if always 

 surrounded by a homogeneous layer of sarcode. If there be 

 similar cells in the latter during life, they subside into the form 

 of a homogeneous sarcode after death, and thus become indistin- 

 guishable ; while in the Gumminese they remain, indicative of 

 a higher state of development — that is, a state in which the his- 



