known Species of Spongilla. 87 



sharp-pointed, smooth. Statoblast globular ; spicules curved, 

 fusiform, gradually sharp-pointed, smooth. 



Loc. Water-pipes of Boston &c., U.S. 



Ohs. Mr. Thomas H. Higgin, F.L.S., of Liverpool, kindly 

 sent me a specimen from the same locality, viz. the water- 

 pipes of Boston, which, when examined, proved to have a 

 similar skeleton-spicule, among which there are a number of 

 minute, curved, fusiform, sharp-pointed acerates so like the 

 flesh-spicules of Spongilla lacustris that, in the absence of 

 statoblasts, I am led to consider it the same species ; and if I 

 am right, then the spicules of the statoblast should be spined, 

 while those of S. pmipercula were of the " same form as those 

 of the skeleton, but not more than half their size ; " so these 

 would be more like statoblast-spicules of S. Carteri. My 

 description of S. paupercula, Bk., is an abbreviated one of 

 that given by Dr. Bowerbank himself [I. c). 



3. Spongilla navicella^ Carter, n. sp. 

 (PL V. tig. 4, a-g.) 



Sponge unknown. Skeleton-spicule curved, fusiform, 

 smooth, gradually sharp-pointed. Statoblast adherent to the 

 twig on which the sponge had grown ; globoelliptical (fig, 4) ; 

 aperture terminal, infundibular (fig. 4, e) • no apparent crust ; 

 chitinous coat (fig. 4, c) encased with a dense layer of minute, 

 stout, short, thick, more or less curved, fusiform, smooth ace- 

 rates, variable in size, becoming so short internally (that is, 

 where they are in immediate contact with the chitinous coat) 

 as to be trapezoidal, or like a little boat or " cocked hat," 

 according to the direction in which they are viewed ; arranged 

 tangentially, crossing each other (fig. 4, d and g). 



Loc. River Amazons. 



Ohs. A few of the statoblasts were found on a small twig 

 in company with S. reticulata^ Bk., and S. pauperciila, Bk., 

 in the Bowerbank collection. They bear evidence of the 

 existence in the river Amazons of a species of Spongilla whose 

 entirety is as yet unknown ; and it is very probable that a 

 further search there would find many such. 



** Minute acei-ates spined. 

 4. Spongilla lacustris, Linn. 



Spongilla lacustris, Bk., No. 20, p. 24, pi. xxxviii. %. 14 ; also No. 21, 

 vol. ii. I. c. and vol. i. p. 342 ; also No. 25, pi. Ix. and No. 16, pp. 510, 

 611. 



S, lacustris auctt. 



Branched ; branches long, round, and sharp-pointed. Colour 



