126 Mr. H. J. Carter on 



composed of tlie spiniferous, elliptical, solid bodies, gives this 

 sponge very much the character of a Geodia • hence the desig- 

 nation. But the alliance is between these Hash-spicules and the 

 bacilliform bodies of Stelletta hacilUfera^ var. robusta, rather 

 than with the siliceous balls of Geodia, as may be seen by 

 their structure and development, together with a reference to 

 the illustrations of the varieties in form assumed by the 

 hacillar flesh-spicules given in connexion with my descrip- 

 tion of 8. bacilUfera, var. robusta (' Annals,' 1883, vol. xi. 

 p. 351, pi. xiv. %. 3,<7). 



Group 26. S T E L L E T T I N P S I N A (new group) . 



32. Stellettinopsis simplex^ Carter (' Annals,' 1879, vol. iii. 

 p. 349, pi. xxviii. figs. 16-18). 



33. Stellettinopsis taberculata. 



Massive, sessile, nodularly tuberculated ; tubercles agglo- 

 merated into groups. Consistence hard. Colour when fresh 

 " dull purple-brown," now dark brown. Surface rough, ^. e. 

 minutely and uniformly granulated. Vents small, numerous, 

 and in the sulci between the agglomerated tubercles. Spicules 

 of two forms, viz. : — 1, skeletal, a large, smooth, acerate, 180 

 by 3-6000ths in. ; 2, flesh-spicule, a minute stellate about 2- 

 BOOOths in. in diameter. Structure from without inwards 

 consisting of a thick dark dermal layer charged with sand and 

 stellates, traversed by the distal ends of the body-spicules 

 which are situated near the surface, followed by a compact 

 body-substance composed of the large acerate spicule imbedded 

 in sarcode of a lighter colour than the dermis charged with 

 the minute stellate. Size 4^ in. high by 4 x 3 horizontally. 



Depth 3 fath. 



34. Stellettinopsis coriacea. 



A large, irregularly shaped {i. e. amorphous) fragment. 

 Massive, enclosing bivalve shells an inch in diameter in its 

 tissue ; partly covered by a remarkably thick smooth skin. 

 Consistence firm. Colour when fresh " dull purple," now 

 dark pinkish slate, turning to madder-red under the action of 

 liq. potassie or nitric acid. Surface characteristically smooth. 

 "Vents in small groups here and there. Spicules of four forms, 

 viz. : — 1 and 2, skeletal, large acerates and acuates about the 

 same dimensions, viz. 324 by 4^-6000ths in. ; 3, small acerates, 

 about 25-6000ths in. ; 4, flesh-spicule, the usual small stellate, 

 about 2-6000ths in. in diameter. The skeletal spicules are 



