COLLECTED BY THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 453 



Like the oxea, the isochelse agree exactly with those of the type in size and 

 shape. Ehlers' measurement of 0'036 mm. for the length of the isochelse seems 

 to be a little above the actual length. Although the Homceodictya structure of 

 the isochelse is not mentioned by Ehlers, it can be clearly seen in some of the 

 isochelse. On the other hand, there are many isochelse here, as in the Scotia 

 specimens, in which this structure cannot be made out. 



Unfortunately the locality of Esper's type-specimen is not known. It seems 

 possible that it may have been obtained in the neighbourhood of the Cape of 

 Good Hope, where other sponges described by Esper were collected. 



Carter (3) describes some sponges from Algoa Bay, and assigns them to 

 Esper's species. They appear to resemble it closely in external appearance as 

 well as in spiculation, although he definitely states that the isochelse do not 

 show an inward bending of the axis. 



Two species of Homceodictya, H. conulosa (Ridley and Dendy) and H. grandis 

 (Ridley and Dendy), were obtained by the Challenger in Simon's Bay, not far 

 from where the Scotia specimens were collected. H. compressa differs from both 

 in external appearance. It differs also from H. conulosa in having oxea which are 

 much shorter than the oxea in the newer species and less than half as thick. On 

 the other hand, its oxea are hardly more than half as thick, and its isochelse are 

 half the size of the corresponding spicules in H. grandis. 



Homceodictya elastica (Vosmaer). (Plate XL, fig. 17.) 



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

 specimen. 



Only one specimen was obtained. It is an upright, branching sponge. The 

 branches are slightly compressed and slender, or they widen out and coalesce into 

 broad, fan-like expansions. They lie more or less in one plane. The sponge is 

 torn from its support; its height is 85 mm. and its breadth is about 115 mm., 

 while the thickness of the branches is about 6 mm. The texture is rather soft and 

 compressible. The surface is minutely hispid owing to the projecting ends of the 

 main skeletal fibres. The oscula are small, averaging about 1 mm. in diameter. 

 They are usually on a level with the surface, but occasionally have a slightly raised 

 rim. They occur scattered in numbers over one side of the sponge and along the 

 margins of the branches. They are not strictly confined to one surface, as some 

 are to be found on the opposite side. The dermal membrane is thin. The pores 

 are numerous; those measured varied between 0'07-0'15 in diameter. 



The colour in spirit is pale greyish yellow. 



The main skeleton is made up of a reticulation of fibres. The principal fibres 

 run vertically upwards from the base of the sponge. They branch, and bending 

 outwards to the surface, they pierce the dermal membrane, and project as short, 



