41 



the gasfcral membranes are larger than those of the canal-walls (id1. XXI, f. 6, 

 7). The latter stand the further apart, and are the smaller, the narrower the 

 canal or cavity is, in the wall of which they are situated. 



The oxydiactine marginalia, which project from the 'annular ridge, form a 

 single or double row. Their average total length is 600 h- . The proximal 

 imbedded ray is smooth, gradually attenuated towards the pointed end and 100- 

 200 /* long ; the distal free ray is also gradually attenuated and pointed, and 

 400-500 ^ long, it is covered with rather short, oblique spines. From the centre 

 of the spicule four pretty high, pointed protuberances, arranged crosswise, arise 

 (pi. XXI, f. 8). 



Macramphidiscs 200 M long are found in very small numbers, scattered singly 

 throughout the parenchyme. Their terminal discs are of medium size, 100 i^ 

 broad and usually hemispherical ; they have 8 broad and spade-hke marginal 

 teeth. Mesamphidiscs are absent. Micramphidiscs of the usual shape and size 

 are abundant in the membranes lining the canals. 



As in Hyalonema, acanthophores occur in the vicinity of the point of 

 insertion of the root-tuft. They are usually spicules with stout rays, covered 

 throughout or only terminally, with thick spines. Stauractines (pi. XXI, f. 11) 

 are most frequent, but other hexactine-derivates, down to diactines, are also met 

 with. 



The basalia have the shape of knitting-needles. They form a slender 

 central cone which extends upwards through the body of the sponge for a 

 distance of 15 cm. Although only a few of them are preserved, and these 

 broken off pretty short, one can see that they have the usual character of Hyalo- 

 nema-basalia. Some of them are over 1 mm. thick. 



The only specimen of Lophophysema inflatum was found in the Andaman 

 Sea 13° 50' 30° N., 93° 26' B. in a depth of 911 m.=498 fth. 



Sempeeella J. E. Gray. 



Semperella cucumis F. E. Sch. 



Plate VIII. 



1895 Semperella cucumis F. E. Sch. in Abli. Prcuss. Ak. 1894 pp. 45-51, Taf. IX, 



To my great delight I found among the " Investigator " sponges three speci- 

 mens belonging to the Hyalonematid genus Semperella. One of these is fully 

 developed, 40 cm. long, 8 cm. broad and very well preserved. Another one, 

 only about 12 cm, long and 2 cm. thick, appears to be a young specimen, 

 part of which has been lost. It is superficially injured and considerably 

 macerated, only the macrosclere supporting-skeleton and here and there a small 

 fragment of the soft parts being preserved. The third specimen is a root-tuft 

 6 



