202 THE ATLANTIC. [chap, i v. 



purple and greenish pigment ; and almost immediately, without 

 any definite intermediate steps, the outer wall is filled with cal- 

 cified tissue — it becomes covered with fine spines and pedicella- 

 rise, a row of tentacular feet come into action round the mouth, 

 the vent appears at tlie posterior extremity of tlie body, and 

 the young assumes nearly the form of the adult. These later 

 changes take place very quickly ; but they are accompanied by 

 the production of so much heavy purple and dark-green pig- 

 ment that it is diflicult to follow them. The viscera are pro- 

 duced at the expense of the abundant yelk ; and the animals at 

 once take a great start in size by the imbibition of water into 

 the prev^isceral cavity. The young urchins jostle one another 

 on the floor of the breeding-pouch, those below pushing the oth- 

 ers up until the upper set are forced out between the rows of 

 fringing spines of the pouch ; but even before leaving the mar- 

 supium, on carefully opening the shell of the young, the intes- 

 tine may be seen already full of dark sand, following much the 

 same course which it follows in the adult. The size of the test 

 of the young on leaving the marsupium is about 2'5 mm. in 

 length by 2 mm. in width. 



We took along with the last species in Stanley Harbor sev- 

 eral sj)ecimens of a large species of Asteracantimi, which form- 

 ed a marsupium after the manner so well described by Sars in 

 EGMnaster Sarsii, Mijllek, by drawing its arms inward and 

 forward, and forming a brood - chamber over the mouth. In 

 some samples of this species the young were so far advanced 

 that when the mother was placed in a jar they crept out of the 

 nursery and wandered over the glass wall of their prison ; this 

 brood had entirely lost the pseudembryonic appendages, but in 

 their younger condition these are very apparent, though scarce- 

 ly so well developed as in the young of A. violaceus on our 

 own coast. 



On the 27th of January, 1874, at Station CXLIX., off Cape 

 Maclear, on the south-east coast of Kerguelen Island, we dredged 



