﻿^5o 



•ENDEAVOUE" SCIENTIFIC EESULTS. 



keep their descriptions separate. The specimen which, on 

 account of its better preservation, 1 select as typical of the 

 species, is divided longitudinally into two equal portions ; one 

 portion has been retained in spirits, the other was removed 



and preserved in a dry state. As a 

 result of its drying the latter has 



A undergone a remarkable amount of 



shrinkage, being now scarcely more 

 than one-half its former size.i The 

 second specimen is both macerated 

 and dry. 



A 



Description. — 



(a) Typical Specimen. The speci- 

 men, when complete, had the form of 

 an oval leaf-shaped plate, with the 

 narrower end drawn out into a short 

 stalk, and measured 120 mm. in 

 height, 90 mm. in greatest breadth 

 and 8 to 10 mm. in thickness. Both 

 surfaces exhibit a number of obscure, 

 longitudinal, somewhat radiately 

 disposed grooves which become more 

 distinct towards the margin. These 

 grooves are apparently due to the 

 presence of canals lying immediately 

 beneath the thin dermal membrane 

 which have caused the latter to 

 undergo a slight collapse. Owing to 

 the somewhat damaged state of the 

 surface, it is impossible to speak with 

 certainty regarding oscula ; it ap- 

 pears that the canals terminate along 

 the margin of the plate in small 

 circular openings. 



The main skeleton is a reticulation of slender fibres which 

 are fairly closely echinated by small acanthostyles. The main 

 fibres contain a slender compact spicular core ; the connecting 

 fibres interreticulate to a slight extent and are destitute of 

 axial spicules. Owing to the paleness of the spongin, the 

 main fibres, by reason of their axial spicules, stand out rather 

 ■conspicuously in comparison with the connecting fibres, so 

 that at first glance the skeleton might appear to be dendritic-; 

 the false impression is, however, immediately corrected by the 

 presence of echinating spicules on the connecting fibres. Both 



Fig. 52— IV. oxyphila. 

 Showing variations of the 

 opposite extremities of 

 the smooth megascleres. 



1 The piece was subsequently returned to alcohol and expanded again 

 ••almost to its original size. 



