394 THE VOYAGE OF H.M.S. CHALLENGER. 



remained on the floor of the central chamber, in which the eggs or the young had 

 evidently been lodged. I have on three occasions in species of the genus Hymenaster 

 found the eggs beneath the membrane in the angles of the arms, and, in a more advanced 

 stage, congregated in the central tent, but never under circumstances such that I could 

 keep and examine them ; exposed or loosely covered eggs or embryos, or any soft and 

 pulpy organs or appendages, are always in a half disintegrated state when they are 

 brought up from such great depths, if they have not been entirely washed away. 



" As I have already said, Hymenaster is closely allied to Pteraster : the arrangements 

 of the marsupium are nearly the same in both ; and it is highly probable that, in 

 Hymenaster, as in Pteraster militaris, a provisional alimentary tract may be developed 

 in the early stages of the embryo. 



Fig. 149.— Hymenaster nobilis, Wyv. Thorns. The marsupial tent with the valves closed. Twice the natural size. 



" There are several fine species of Hymenaster within reach of British naturalists in 

 the deep water at the entrance of the Channel and off Cape Clear ; but I fear there will 

 be great difliculty in determining this point unless the genus turn up somewdiere in 

 shallower soundings where specimens can be taken alive. 



" In Stanley Harbour, on the roots of Macrocystis, and also brought up free by the 

 dredge, there were numerous examples of an Ophiurid which appears to correspond with 

 Ophiacantha vivipara, Ljungman ; we had previously got either the same or a very 

 closely allied form in great abundance in the fjords of Kerguelen. The Kerguelen 

 variety has been noticed by Mr. Edgar A. Smith, 1 under the name of Ophioglypha hexavtis, 

 and I have called it, provisionally, in a paper in the Proceedings of the Linnsean Society, 

 Ophiocoma didelphis, from its opossum-like habit of carrying its young upon its back. 



1 Ann. and Mug. Nut. Hist., sur. 4, vol. xvii. p. 3, 1876. 



