II. Descriptive part. 



I. CALCAREA. 



Grantia intermedia Thicker. 



PL II. fig. 1. 



Vide Litter: 32 pag. 770. 



St. 102. Two specimens. 



Of the two small egg-shaped sponges collected at 

 this station, one is about 14 mm. high by 4 mm. broad 

 with a well developed oscular fringe, about 1 mm. in 

 length, round a conspicuous osculum at the summit; the 

 other is 9 mm. high by 4 mm. broad, with an oscular 

 fringe 1 mm. in length. Colour in spirit pale brown. 

 Surface coarsely hispid with large oxeote spicules projec- 

 ting in different directions. The thickness of the wall in 

 the larger specimen is about 1.7 mm. of which about 

 0.14 mm. come on the dermal cortex, the rest on the 

 chamber layer and the feebly developed gastral cortex. 



I have not been able to trace the canal system, but 

 the tubar skeleton shows a conspicuous articulate construc- 

 tion, though with slight signs ot becoming scattered. 

 The skeleton consists of triradiate, quadriradiate and oxeote 

 spicules. 



In the cortex the vast majority are triradiates, but 

 quadriradiates may occur. The triradiates are usually, 

 irregular, showing a tendency to become sagittal. The 

 rays are bent or straight, and of variable length, ordinarily 

 about 0.37 mm. long by 0.014 mm. thick (resembling 

 Thacker's figures. Textfig. 162 a. op. cit). 



The tubar skeleton is composed as far as I could 

 make out exclusively of quadriradiates, the facial rays of 

 which form the walls of the six-sided skeletal tube, while 

 the apical ray emerging from each angle projects into the 

 lumen. They are usually sagittal with an oral angle of 

 about 120"; the longest of the facial rays is about 0.440 

 mm. and the other two about 0.270 mm.; the apical ray 

 is only about 0.030 mm. All the rays are of the same 

 thicknes and resemble the triradiates. 



The thin gastral cortex is composed of quadriradiates 

 intermingled with triradiates both of about the same shape 

 as those occurring in the tubar and dermal skeleton. The 

 apical ray — somewhat longer than in the quadriradiates of 

 the chamber layer — projects into the gastral cavity. 



Large, oxeote spicules emerge from the surface of the 

 sponge without definite order at different angles. Their 

 proximal ends are hidden in the tubar layer of the body- 

 wall. They are spindle shaped, usually not sharply poin- 

 ted at the ends. They were all broken, so that I have 

 not been able to measure their length exactly, but most 

 certainly they are at least about 2—3 mm. long with a 

 thicknes varying between 0.04 — 0.07 mm. The oxeote 

 spicules composing the oscular fringe are very long and 

 fine, reaching a length of 2—3 mm. and a thicknes of 

 0.004-0.008 mm. 



Remark: Grantia intermedia T hacker, has been 

 found once off Cape Verde (Crossland Collection) at a 

 depth of 20 fathoms (Boa Vista Island). Thus belonging 

 to the warm water fauna, while the form here described 

 has been dredged north of the Wywille Thomson ridge 

 (st. 102), at a depth of 1098 m. 



This great difference in habitat makes it perhaps 

 uncertain that they belong to the same species, but they 

 agree so well in anatomical structure, except that the tubar 

 skeleton here is exclusively composed of quadriradiates 

 instead of triradiates intermingled with quadrtadiates as in 

 the type — a feature, which in the meantime cannot be 

 held to justify a separation into two species. 



Locality: North of the Wywille Thomson Ridge 

 (Lat 60° 57' N, Long 4" 38' W); depth 1098 m.: 

 bottom blue mud. 



II. SILICEA. 



Euplectella suberea Wywille Thomson. 



PI. I, fig. 1. 



Vide Litter: 30 pag. 9. 



St. 25. Several fragments (about 15). 



The specimens obtained are all in rather bad condi- 

 tion, but nevertheless they are doubtless to be recognized 

 as Euplectella suberea Wywille Thomson. 



Usually they consist only of the basal tuft with a small 

 remnant of the body-wall. Only one specimen, though 

 also much damaged, represents the entire sponge, in 

 which only traces of the tuft are left. This specimen has 

 a subcylindrical form and is 10 cm. high with a diameter 



