SPONGES. 263 



ANTHASPIDELLA FIRMA U. & H. 



PL H, fig. 3, 3a. 



Of this sponge the specimen figured is the only one observed.* 

 Its shape is obliquely depressed-obconical, the cup shallow, and 

 its margin acute, the stem strong, and apparently very short. 

 The under surface shows two faint constrictions, besides several 

 nodular protuberances. The furrows are strong, four to six in 

 10 mm., and more or less irregularly interrupted, being espe- 

 cially so upon the shorter side. The comparatively large, oval 

 or circular mouths of the radiating channels, are visible in the 

 bottom of the furrows. About seven occur in 10 mm. 



The oscula of the upper surface are deeply impressed, irregu- 

 larly stellate, of moderate size, and the twenty-seven that can 

 be determined are confined to the inner two-thirds of the cup; 

 the canals which radiate from them, are strong and usually 

 proceed but a short distance when their diameter is diminished, 

 and their identity lost in the confused canal-network prevailing 

 over the central portion of the surface. It is only toward the 

 margin of the cup that the channels assume a common radiate 

 arrangement : yet. even here, they inosculate rather freely. 



The canal system, as shown by cutting the specimen vertically 

 through the centre, proves to be in all important particulars 

 considerably like that of A. florifera. The canals, however, are 

 larger and the radiating canals less curved downward at their 

 outer ends, appearing also, much less continuous in the section. 



Height of sponge about 50 mm.; greatest diameter of cup, 

 92 mm.; depth of same 13 mm.; diameter of stem, where broken 

 about 25 mm. 



The canals of this species are larger and more widely separ- 

 ated than in any other of the species here described, and as 

 the type specimen differs more or less obviously in other re- 

 spects from them, it is difficult to decide to which A. firma is 

 the most closely related. These peculiarities, however, are only 

 of specific importance, and the species is clearly congeneric with 

 A. mammulata. 



* Another specimen of this species was collected lately by Mr. TJlrich. 



