COLLECTED BY THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 463 



Reniera saldanhae n. sp. (Plate XXXIX, fig. 8 ; Plate XL, fig. 18.) 



Station 482. Reit's Bay, Saldanha Bay, shore. 21st May 1904. Four specimens. 



Station 483. Entrance to Saldanha Bay, 25 fathoms. 21st May 1904. Five 

 specimens. 



Although differing somewhat in shape the specimens bear a general resemblance 

 to each other externally. They consist for the most part of coalescent, rather thick 

 walled tubes, rounded off at the base in the complete specimens and not tapering 

 into a stalk. The largest specimen is 65 mm. high by 80 mm. in breadth. It is 

 broken in two and is otherwise rather injured, but like most of the smaller, perfect 

 specimens, it shows no sign of having been attached to any support. It consists 

 of about eight tubes, closely united. Another specimen, nearly as large, consists of 

 a fewer number of wider tubes. A third specimen, 90 mm. by 40 mm., is an oval 

 cushion-like mass, rather unlike the other specimens in shape. Several smaller 

 specimens, which were collected between tide-marks, consist of three or more 

 coalescent tubes. They are unbroken and have an irregularly rounded outline, but 

 are compressed from side to side. They were not fixed to any support. A small 

 specimen, 20 mm. by 8 mm., growing on a hydroid colony, apparently belongs to 

 this species. 



The surface of the specimens is even, but seen under the lens it is very finely hispid. 

 The dermal membrane is thin and is pierced by numerous pores. Those measured 

 were from 0*02-0'06 mm. in diameter. The oscula vary in diameter from 3-12 mm. 

 Each leads into a wide oscular canal, which, in most of the specimens, runs to the 

 base of the sponge. The canal is at first the same width as the osculum, but 

 narrows as it reaches the base of the sponge. The consistence is firm, but is 

 compressible, as there is rather a large amount of spongin present cementing the 

 ends of the spicules. 



The colour in spirit is pale greyish yellow. 



The largest specimen contains numerous embryos, which are about 0'15 mm. in 

 diameter. Numerous small oxea are present in the older embryos. 



The main skeleton consists of a unispicular network with usually quadratic 

 meshes. The ends of the spicules are embedded in spongin, of which there is a 

 considerable quantity present. Here and there rather ill-defined fibres, containing 

 two, three, or more rows of spicules, run more or less vertically through the sponge. 

 At the surface the ends of the spicules pierce the dermal membrane and project very 

 slightly beyond it. There is no special dermal skeleton. 



Spicules. — Oxea, curved, evenly pointed, 0'15-0*185 mm. long, with a maximum 

 diameter of 0'013 mm. The oxea in the embryos are, on the whole, 0'06-0'08 mm. 

 long, with a maximum diameter of 0"0025 mm. 



TRANS. ROY. SOC. EDIN., VOL. L, PART II (NO. 15). 65 



