260 PROCEEDINGS OF THE ACADEMY OF [1887. 



Gemmules numerous, without attachment, resting within open- 

 meshed capsules, through which the crust expands itself in many 

 large and irregularly rounded lobes, composed of large parenchymal 

 cells filled with granular matter,^ beneath which, in a single layer, 

 the parmuliform spicules rest in a normal fashion upon the chitinous 

 coat. 



Skeleton spicules almost indistinguishable from those of the 

 supporting species ; their principal feature being, that they are loosely 

 aggregated and never occur in bundles of fasciculated lines. 



No dermal spicules seen. 



Parmuliform gemmule spicules rest upon the chitinous coat, and 

 from above them the parenchymal crust easily separates. 



Hah. Only known within the meshes of P. brownii. 



Loc. Beni River, etc. S. A. 



The characteristic gemmules of this species (?) were first noticed 

 among the debris of the above named variety. After an earnest 

 effort to determine their origin and associations, they were at last 

 traced to certain minute flocculent masses of indefinite shapes resting 

 among the spicular lines of that sponge. The gemmules certainly 

 differ in type from those of either of the before described species, 

 and but one other solution occurs to me, besides that which I have 

 adopted ; viz. making it a new species; and this is, the possibility, 

 barely a possibility, that they pertain to the principal sponge, as errant 

 or floating gemmules, for the distribution of the species ; as the more 

 common and normal forms of P. brownii are so heavily weighted 

 with capsular and skeleton spicules that when detached, they sink 

 promptly to the depths of the water. 



Pending the solution of this problem, I name it as a provisional 



species after Dr. Rusby, from whom science has received much and 



hopes for more. 



(VI) Gen. CARTERIUS, Potts. 



Carterella, Potts & Mills; Proc. Acad. Nat. Sci. 1881, p. 150. 

 Gen. Char. Skeleton spicules as in Spongilla or Meyenia. Gem- 

 mulse globular, the chitinous coat around the foramina! aperture 



^A re examination of several mounted specimens of I', rusbyi, made with a 

 view to affirm or disprove certain suggestions of my friend Carter, lias convinced me 

 that \.\\Q granular tnaltcr, above spoken of in this and probably also in other cases, 

 differs from that condition of the crust that has been called cellular in no other 

 respect tiian in the size of the cells. The large parenchymal cells in this case, 

 therefore, contain within them or are subdivided into, immense numbers of the 

 smaller kind. It should be said that Mr. Carter prefers to consider this a mere 

 variety oi P. brownii. 



