CHAP. IV.] THE VOYAGE HOME. 205 



they entirely free themselves, wliich they do when the number 

 of tentacular feet on each arm has reached about twenty, they 

 cluster in the re-entering angles between the arms of the moth- 

 er, spreading a little way along the arms and on the dorsal sur- 

 face of the disk ; the young escajDe from the marsupium chiefly 

 in the neighborhood of the angles between the rays. The mad- 

 reporiform tubercle is visible in the young near the margin of 

 the disk between two of the arms ; but in the mature star-fish 

 it is completely hidden by the paxilli, and no doubt it opens 

 into the space beneath them. 



We took Lej)tychaster in the act of bringing forth young on 

 that one occasion only ; and the weather was so boisterous at the 

 time that it was impossible to trace the early stages in the devel- 

 opment of the embryo. It is evident that the process generally 

 resembles that described by Professor Sars in Pteraster milita- 

 rise and it is quite possible that, while there is certainly not the 

 least approach to the formation of a locomotive bipinnaria, as in 

 that species, some provisional organs may exist at an early period. 



In " The Depths of the Sea " (p. 120) I noticed and figured 

 a singular little star-fish from a depth of 500 fathoms, off the 

 North of Scotland, under the name of Hymenaster pellucidus. 

 This form was at that time the type of a new genus ; but the 

 researches of the last three years have shown that, with the ex- 

 ception perhaps of Archaster, Hymenaster is the most widely 

 distributed genus of Asterids in deep water. It is met with 

 (sparingly, it is true, only one or two specimens being usually 

 taken at once in the trawl) in all parts of the great ocean ; and 

 it ranges in depth from 400 to about 2500 fathoms. 



On the 7th of March, 1874, we dredged an extremely hand- 

 some new form, to which I shall give provisionally the name of 

 Hymenaster nobilis, in lat. 50° 1' S., long. 123° 4' E., 1099 miles 

 south-west of Cape Otway, Australia, at a depth of 1800 fath- 

 oms, with a bottom of globigedna ooze, and a bottom tempera- 

 ture of 0°'3 C. 



