70 



MR. H. J. CARTER ON A COLLECTION OF 



apart, but nearly equidistant from each other, resembles Isodictya 

 densa, Bowerb. (Mon. Brit. Spong. vol. iii. pi. 50. fig. 5). No. 55 

 (Pi. VI. fig. 2) and that on the base of Esperia indica (No. 54) 

 are much the same but without the vents on the surface, and this 

 variety might be termed " incrustans." Lastly, Nos. 59 (Pi. VI. 

 fig. 1) and 15 are branched fragments (some of which measure 



3 inches in their longest diameter) of a large specimen which, from 

 its fragility, has become broken into pieces. In its original state, 

 the sponge consisted of a mass of short branches united with each 

 other and tubulated, so that a large terminal vent is present in the 

 free end of each branch. For this variety, which is the most 

 characteristic of all, I would suggest the name of " tubuloramosa." 

 It comes nearest in character to the British form of the species, 

 and the specimen which represents it must when perfect have 

 been of considerable size. 



Thaltsias tener, n. sp. 



Densely ramose ; sessile or stipitate; branches tubular, short, 

 thick, crooked and anastomosing, ending on a horizontal sur- 

 face. Consistence light, fragile. Colour light brown. Surface 

 uniformly but irregularly pitted, covered with a delicately 

 reticulate dermal structure. Vents large, numerous, and cir- 

 cular; placed on the sides or at the ends of the branches. 

 Internal structure consisting of fibres intermixed with isodictyal 

 tissue. Spicules of one form only, viz. acerate, smooth, fusiform, 

 curved, sharp-pointed, about 40 by 2-6000ths inch in its greatest 

 dimensions. Size of largest specimen, which is stipitate, about 



4 inches in horizontal diameter and 3 inches high. 

 Loc. King Island. 



Obs. The chief difference between this and the last species 

 is caused by the 'presence of fibres among the isodictyal tissue, 

 which show themselves in a beautiful manner through the delicate 

 dermal network that veils the surface. It chiefly differs from 

 the West-Indian species, viz. T. sub triangularis, Duch. & Mich., 

 and its varieties in being less compact and much more tender in 

 structure; otherwise it seems to be the representative of the 

 latter in these parts. The adnate fragments, growing on rock, 

 viz. Nos. 14 and 21, must bo viewed as young individuals. It 

 belongs to that division of the Kenierid family in my classifi- 

 cation which has been termed (" Thalysiosa ") Thalyosa. 



