Sponges from South Australia. 507 



cih'ata, in which it is directed outwards, it should here be in the 

 opposite direction, viz. towards the cloaca ; while the reproduc- 

 tive elements, viz. large ova presenting the germinal vesicle, as 

 will be more particularly described presently, are on the inyier 

 surface of the ecMnated tube ; therefore the analogy here is not 

 between the echinated tubes and the cloaca of Grantia ciliata^ 

 but between the echinated tubes and the radial chambers of 

 the latter ; while the '' intervals'" would be analogous to the 

 intercameral spaces or " intercanal system " of Hackel. 



It may also be observed that the spiculation would be iden- 

 tical with that of my Leucetta datlirata ('Annals,' 188.S, 

 vol. xi. p. 33, pi. i. figs. 13-17), which came from the south- 

 west coast of Australia, but for the presence of the quadri- 

 radiate spicule, and tlie comparatively scanty presence of the 

 trijiod spicules on the ridges of the surface. 



The Auloplegma-form is plentifully charged with ova filled 

 with minute spherical granules, in the midst of wliich is the 

 germinal vesicle &c. The ova are about l-24th in. in dia- 

 meter, the germinal vesicle about l-1200th, and the germinal 

 spot 1 -6000th in, in diameter. There are also much smaller 

 nucleated granuliferous cells about twice as large as the spou- 

 gozoa, that is about l-2000th in. in diameter. What may 

 they be ? 



Besides this the specimen is abundantly infested by a 

 minute oscillatorian filament in bacillform fragments of diffe- 

 rent lengths, very much resembling in form the Trichodes- 

 mium Ehrenhergii which colours the Red Sea. 



4. Clathrina tripodifera, var. gravida. 



Individualized. Small when compared with the foregoing 

 specimens, to which it will be found to be closely allied. 

 Triangular, compressed, contracted towards the base or point 

 of attachment, expanded above, composed of tortuous, branch- 

 ing, anastomosing reticulate tubulation more or less intersti- 

 tially separate. Colour sponge-brown when fresh, whitish 

 yellow when dry. Surface uniformly even, retiform, con- 

 sisting of the superficial part of the tubular reticulation of 

 which the whole body is composed, rendered prominent and 

 glistening by a great abundance of the tripod spicules. Pores 

 in the wall of the tubulation throughout. Vent-like open- 

 ings three or four in number, chiefly in the upper border, 

 defined by simple circular apertures in the general tissue, 

 not marginated, leading into cloacal cavities below, which 

 consist of equally simple dilatations of the reticulate tubu- 

 lation at this part. Structure generally consisting of a 

 minute, tortuous, branching and anastomosing hollow thread 



35* 



