CHONDEILLA. 69 



bourhood of Port Phillip Heads, South Australia, Ann. & Mag. Nat. Hist, 

 ser. 5, vol. xv. p. 196), Proceedings of the Liunean Society of New South 

 Wales, vol. x. part 2, p. ] 52 (1885). 



I named this sponge the second to commemorate the fact that it was, of the 

 thousands of different forms collected by me in Australia, the second specimen 

 I found. 



Our sponge represents in outer appearance a lamellar or irregular bulbous 

 mass ; the lamellar shape being the most frequent. The lamellsD are not of 

 uniform thickness throughout ; they attain an average size of 30 x 60 millim. 

 and more, and measure in the thickest part 12 millim. in diameter ; in 

 places these lamellae are very thin, or even pierced so as to present a 

 sieve-like appearance. The bulbous variety of this species is not large, it is 

 spherical, attains a diameter of 25-35 millim., and is attached to stones &c. 

 by a small basis only ; also the inore frequent lamellar form is attached to 

 stones by small parts of its lower surface only. I obtained most of my speci- 

 mens adrift. 



The surface is perfectly smooth. The colour is subject to similar variations 

 as in some European species, and varies from light dull yellowish grey to dark 

 bluish black. Mostly the side exposed to the light seems to be of a darker 

 colour than the other. However, a strict rule can be established here as little 

 as in the case of C7io)idrosia reniformis. The colour of the outer surface is 

 alone subject to these variations ; the interior of the sponge always has the 

 same dull grey colour. The oscula are raised slightly over the surrounding 

 surface, 3-6 in number ; they are always situated on the upperside of flat 

 specimens, are circular, and measure 2-3 millim. in diameter. The bulbous 

 specimens have only one osculum. The dark parts of the cortical layer are 

 non-transparent in consequence of the great number of pigment granules ; 

 the light parts are more transparent and better suited for investigation. 

 The outermost zone always appears radially striped in consequence of the 

 inhalant canals being vertical to the surface in their distal portion. 



Structure.— Our species does not seem to differ from Chondrilla nucula in any 

 respect except in the shape of the spicules. There are two kinds of spicules ; 

 both kinds are met with not very abundantly throughout the sponge ; towards 

 the outer surface and particularly also in the canal-walls they become much 

 more numerous. The larger kind measures 0-064 millim., the smaller kind 

 0-012 millim. in diameter. The spines of the larger kind are about 0-006 

 millim. long and 0-004 millim. broad ; the spines of the smaller kind measure 

 0-003 X 0-001 millim. The larger spicule has the shape of a ball with distant 

 short and smooth spines, which are terminally rounded ; the surface of the 

 central sphere is clearly visible between the spines. In the small spicule the 

 spines are pointed and relatively much longer, three times as long as broad at 



