458 JANE STEPHENS: ATLANTIC SPONGES 



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

 specimens. 



The external appearance of several specimens of Siphonochalina obtained in 

 Table Bay resembles very closely Esper's figure of Spongia tubulosa (7, pi. liv), 

 while the structure of the skeleton and the size of the spicules agree so well with 

 Ehlers' description (6) of the same specimen that there seems no reason to doubt 

 the identity of the Scotia specimens with Esper's species. The locality, too, is 

 practically the same, as the specimen described by Esper was found at the Cape of 

 Good Hope. Through the kindness of Professor Zimmer a search for the type- 

 specimen was made among the Esper collection of sponges, now in Munich, but 

 without success. 



The largest specimen is about 18 cm. by 13 cm. in diameter, with a height of 

 7 cm. It consists of a number of rather short, wide tubes 15-20 mm. in diameter, 

 united at the base. These usually coalesce for a greater or less distance, and some- 

 times to such an extent that they are united for their whole length, so that ridges 

 are formed pierced at intervals by oscula. In one specimen, 15 cm. by 13 cm., the 

 tubes are so united that their limits cannot be made out, and in one part only of 

 the sponge are the characteristic tubes seen. The summits of the tubes are rounded 

 so that the edges of the oscula do not project above the tops of the tubes. The 

 oscula are often about 5 mm. in diameter, but they vary from 2 to 7 mm. The 

 tubes of the type-specimen seem to be rather worn and frayed out at their summits. 



The colour in spirit is dark yellowish brown. The consistence is firm, but com- 

 pressible. The surface is minutely hispid, and the dermal membrane is thin and 

 transparent. The pores are closely set. Those measured varied between 0'025- 

 0"175 mm. 



In addition to the large specimens collected in Table Bay, some small specimens 

 were obtained in Saldanha Bay. Allowing for the difference in size, the smaller 

 specimens agree very closely in general appearance with the large ones. They are 

 not so dark, being of a pale yellowish colour. Some have tubes coalescent to their 

 summits, others have tubes which are more or less free except at the base. Thus 

 one small specimen agrees in appearance with a certain part of one of the large 

 specimens where the tubes are coalescent, and another young sponge agrees with a 

 different part of the same specimen where the tubes are free. One specimen is 

 growing over a Laminaria-\ike root, but two or three of the remaining specimens 

 show no sign of having been attached to any support. The smallest specimen is 

 67 mm. high by 38 mm. in width. 



The main skeleton consists of a reticulation of fibres. The principal fibres curve 

 upwards and outwards from the irregular network of fibres immediately beneath the 

 membrane of the oscular canal to the surface of the sponge, where they pierce 

 the dermis and project as short, compact tufts of spicules. They consist of a core 

 of multiserially arranged oxea covered with a distinct sheath of spongin. They 



