274 HAWAIIAN AND OTHER PACIFIC ECHINI. 



South America, Falkland Islands, and Marion Islands, its specific rank seems 

 probable. On the other hand, the variety Hassleri is not at all constant, and as 

 specimens from Marion Island resemble it very closely, it is clear it has no fixed 

 geographical limits. There are more than a dozen bare tests of what seem to be 

 magellanicus from Australia and New Zealand in the M. C. Z. Four of these 

 are labelled albocinctus and were received from Captain Hutton himself. After 

 a careful study of these tests and Benham's description (1908, Ann. Mag. Nat. 

 Hist., (8), I, p. 107), we have failed to find any character by which albocinctus 

 can be distinguished from magellanicus, for even the globiferous pedicellarise, 

 upon which Mortensen bases his placing of the two species in separate families, 

 are quite unreliable. It may well be granted that most New Zealand speci- 

 mens have the valves of the globiferous pedicellariae with a lateral tooth only 

 on one side, although no personal observations support such a view; that such 

 is the case uniformly seems very doubtful. In the light of all the evidence 

 available, it is probable that magellanicus is a circumpolar, subantarctic sea- 

 urchin, wanting on the South African coast, but without doubt occurring on 

 most of the other continental coasts, and on the islands, between 30 and 60 S. 

 lat. On the isolated island of New Amsterdam, it has become differentiated 

 into a well-marked variety, and possibly a New Zealand variety (albocinctus) 

 may be entitled to recognition. In New Zealand, moreover, a species has arisen, 

 Huttoni, which though nearly allied to magellanicus, seems to be well distinguished 

 by the much finer tuberculation of the test and some associated characters. 

 It is to be hoped that some New Zealand zoologist will soon determine, from the 

 study of good series of fresh material, the true relationships of albocinctus, 

 Huttoni, and magellanicus. 



The four valid species of Parechinus may be distinguished as follows: 



Buccal membrane with more or less numerous plates (besides the primordial ambula- 

 crals) some of which are often thickened and bear pedicellariae. 



Primary spines not banded angulosus. 



Primary spines with 2-3 brown rings annulatus. 



Buccal membrane thin and except for primordial ambulacrals, perfectly bare, or rarely 

 with a few minute plates. 



Primary tubercles large and distinct, easily distinguished from secondaries, not 

 pink or pinkish orange; coloration variable magellanicus. 



Primary tubercles very small, not occupying half the height of interambulacral 

 plates at ambitus, forming with the similar secondaries a horizontal row of 8-10 

 tubercles on each interambulacral plate at ambitus; outer half of this row 

 often double; test white or light yellowish brown; tubercles pink or pinkish 

 orange; primary spines pink or red at base, distally white Huttoni. 



