450 JANE STEPHENS: ATLANTIC SPONGES 



They are slightly crooked, a character not mentioned in the original description, but 

 which is shown in the figure given (15, pi. xv, fig. 7). 



The rosette anisochelse are a little smaller in the Scotia specimens than in the 

 type, but their proportions are exactly similar. They measure 0'065 mm. in total 

 length, while the larger alse are 0'032 mm. in length and are the same in breadth. 

 The medium-sized anisochelse are 0'03 mm. long, with the larger alse 0*02 mm. in 

 length by 0*013 mm. in breadth. The smallest anisochelse are 0'013 mm. in length, 

 with the larger alse 0*008 mm. long. The sigmata are slightly smaller than in the 

 type, the maximum measurement being about 0*18 mm. for the length and 0'013 mm. 

 for the thickness. Young sigmata are to be seen of about the same length, but only 

 about 0*003 mm. thick. The toxa vary a good deal in length, being usually 0*15 mm. 

 long, but they may be found up to 0*2 or 0*3 mm., a length which some of the toxa 

 in the type-specimen reach, as may be seen from a preparation in the British 

 Museum. 



The species has hitherto only been obtained by the Challenger Expedition. It 

 was dredged in Simon's Bay, Cape of Good Hope, in 10-20 fathoms (15). 



Mycale sp. 



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



Several pieces of a Mycale were found, which are too fragmentary to name, 

 consisting as they do chiefly of macerated fibres, with most of the microscleres 

 washed away. The following kinds of spicules were obtained from one fragment 

 in a rather better state of preservation : — Subtylostyli, 0*25 mm. in length by 

 0*008 mm. ; anisochelse, 0*025 mm. and 0*05 mm. in length ; sigmata, 0*08-0*1 mm. 

 long ; toxa, with well-rounded curve in the middle of the spicule, up to 0*14 mm. long. 



Esperiopsis informis n. sp. (Plate XL, fig. 11.) 



Station 478. Table Bay, shore. May 1904. 



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



This species is represented by several pieces, more or less broken. They are 

 encrusting the base of hydroid colonies, the stems of which are growing through the 

 sponge. The Table Bay specimen is growing on a Laminaria-like root. 



The texture of the sponge is rather firm, and the surface is slightly hispid. The 

 oscula are on a level with the general surface of the sponge and are about 1-2 mm. 

 in diameter. The dermal membrane is thin and is pierced by numerous pores. 



The colour in spirit is pale greyish yellow. 



The main skeleton is made up of a network of fibres. The principal fibres, which 

 consist of multiserially arranged styli, run vertically through the sponge. They 

 pierce the dermal membrane and project slightly beyond the surface of the sponge 

 as tufts of spicules. They are about 0*15-0*2 mm. apart, and are connected by 



