Sponges from South Australia. 141 



adopted Dr. Gray's name. Hackel's " connective variety," 

 viz. Leucandra pulvinar (p. 164), is said to present the 

 quadriradiate j but as no other part of the spiculation is men- 

 tioned, we must assume here that it was the same as that of 

 liis typical species " Leucortts jjulvinarj^ 



I have ah-eady alluded to the fork-like spicule as being 

 interesting, because it has been discovered in a fossilized 

 Calcisponge from the " Cretaceous " {l. c.) ; but the largest 

 and most perfect that I could find in the mounted slice of 

 Sestrostomella ru/josaj in wiiich it was first noticed by Dr. 

 Hinde, who kindly lent it to me for examination, is not quite 

 half so large as the largest that I have been able to see in 

 Lelapia auslralis^ added to whicii the shaft was lanceolate at the 

 end in the fossil as in \\\a\ oi Leucetta ijandora, represented by 

 Hackel (Taf. xxiii. &c.), and not simply pointed like all those 

 that I have seen in Lelapia australis ; but we know that 

 position may influence these trifling differences, and even 

 those two figured by Dr. Bowerbank {op. et loc. cit.) are not 

 alike in this respect, the shaft in one being simply pointed 

 and in the other inflated before the end or lanceolate. 



It is remarkable too that the two arms ivithout the shaft 

 should bear considerable resemblance to the forcipitous flesh- 

 spicule in the genus Forcepia among the siliceous sponges 

 {Halichondrta forcepisj Bk., Mon. B. Sp. vol. iii. pi. xliii. 

 fig. 13), wherein also the arms are long, parallelly approxi- 

 mated, and of unequal length. In one it is the arms of a 

 triradiate and in the other a bent acerate. 



Ohservation. 



We have now come to species of Leuconia in which the 

 typical form of the " cloaca " no longer exists, and this was 

 initiated by the division and indistinctly circumscribed condi- 

 tion of these cavities in Aphroceras alcicornis snad Leucogypsia 

 Gossei ; there is no longer any peristome, and both this and 

 the cloaca in the following species will at last be found to 

 disappear altogether, when the excretory canals, which hitherto 

 have ended in a cloacal dilatation and peristomed vent, will 

 be found to open directly on the surface without the interven- 

 tion of either. 



37. Leuconia multifida. 



Agglomerated. Specimen sessile, massive, compressed, 

 irregularly undulating on the margin, which is thus divided 

 into five more or less conical and projecting portions, each 

 provided with a mouth, but no peristome. Colour whitish 



