ECHINOIDEA. I. 



i8i 



esctilctifns van f€nuispinn (p. 162), and so it "ets tlie name of Echinus tenuispinus u. sp. It is, as 



seen by Norman, closely allied to esculentns^ with which it a<^rees in the most important characters: 



primary tubercle onl\- on every other ambnlacral plate, and s])ines on the buccal plates; it is easily 



distinguished from the latter b>- having far fewer 



tubercles, among which the primary series are ver\ 



distinct, and by its white colour — rsculnifus seems 



alwajs to keep the colour in spirit. I am decidedly of 



opinion that it must be regarded as an independent 



species, not only as a variet)- of csciilrnfits. It differs 



considerably as to habitus from this species, among 



whose forms I know no specimens with which it ma>- 



be confounded. What I, above (p. 162), have interpreted 



as van tcnuispimis^ is a peculiar form with short, fine 



spines, but with the usual colour of the test (from tlie 



Faroe Islands); accordingly it is not identical with 



Norman's van tenuispinus. 



</.Strongylocentrotus !> lividnsi^. 165) is by S 1 u i t e r (371 ) 

 mentioned from Dogger Bank — it is Str. drobacliiensis. 



Finally I shall call attention to the fact that no single regular Echinid belongs to the large 

 cold depth north of Iceland. The account of the geographical distribution must otherwise be put off 

 until the whole Echinid-material has been examined. 



Fig. 12. Echinus tenuispinus n. sp. Natural .size. 

 (From a photograph.) 



