EEPOKT ON THE HEXACTINELLIDA. 



203 



essential points of structure, but was more conical in form. The young specimen 

 differed from the young of Ilyalonema lusitanicum at the same age in being 

 wider and more cylindrical, but the external wall, which afterwards becomes that of the 

 lower surface, showed the same arrangement in squares which we find in the young of 

 the other species, so that apparently the graceful, round-meshed, wide netting of the 

 under surface does not appear in the early stages. 



"The coil is developed much in the same proportion and in the same way as in 

 Hyalonema lusitanicum, the filjres spreading out and incorporating with the sponge 

 substance. The characteristic bow-like spicules are abundant in the young sponge, and 



Fig. 7. — Hyalonema toxeres, Wyville Thoinsou. Part of the membraue from the upper surface, x 40. 



these, with the larger amphidiscs, place it beyond a doulit that it is the young of 

 Hyalonema toxeres. 



" A quantity of loose spicules brought up in the dredge at the same time were referred 

 to this species. They were somewhat stouter than those of Hyalonema lusitanicum, and 

 less regular in outline. There was one coil nearly complete, involved in a calcareous 

 expansion of a branch of Diplolielia 'profunda. Two very young polyps, apj)arently of 

 Palythoa fatua, were commencing the formation of theii- investing crust at the top of 

 the coil of the young specimen, just below the sponge body." 



Since the three specimens studied by Wyville Thomson are also at my disposal for 



