122 bulletin: museum of comparative zoology. 



kcral plates show radiating lines on the outer half, corresponding in number to 

 the pairs of pores, as in larger specimens of niidus. The test is dull purplish 

 with an evident greenish cast abactinally, and the primary spines and secondaries 

 are more or less greenish. The color is thus quite unlike that of adult nudus. 



Station 5018. Off Cape Tonin, Saghalin Island, 100 fathoms. 



One specimen. 



Strongylocentrotus tuberculatus Br. 



Echinus tuberculatus Lamarck, 1816. Anim. s. Vert., 3, p. 50. 

 Strongylocentrotus tuberculatus Brandt, 1835. Prod. Desc. Anim., p. 264. 



The specimens are all (except one) large and of a very deep reddish-purple color. 



Hakodate. 



Station 4807. Between Hakodate and Sado Island, Japan, 44-47 fathoms. 



Six specimens. 



Strongylocentrotus echinoides A. Ag. and Clark. 



It is hard to believe that a littoral Echinoid as common as this species seems to 

 be, and as conspicuous, is still undescribed, but we are entirely at a loss in the 

 attempt to assign it to any known species. The specimens range from 10 to 72 

 mm. in diameter. The general appearance and coloration in most of the adults, 

 are quite like an Echinus, but the arrangement of the pores, in arcs of seven pairs 

 (six in small specimens) is like Strongylocentrotus, and the pedicellariae of all 

 four kinds are scarcely distinguishable from those of Drbbachiensis. The height 

 of the test varies greatly, ranging from .45 of the diameter to .55. The color is 

 equally variable but the test is more or less reddish-white, darkest on the abactinal 

 median interambulacral areas which may be even deep reddish-purple. The 

 small spines are light greenish, but the primaries show considerable diversity. 

 They are commonly dull reddish at the base, becoming very light greenish at the 

 tip, but in some cases, they are wholly green and in others, wholly light red. 

 They are rather long (10-15 mm.), slender and pointed, but not at all numerous. 

 In each interambulacrum, there are two vertical series of 12-20 large tubercles, 

 each of which is flanked on each side by a less regular row of much smaller 

 tubercles. In each ambulacrum, the median area is bounded on each side by a 

 scries of 18-30 tubercles, slightly smaller than the largest of those in the inter- 

 ambulacra, and between these two series are two less complete rows of much 

 smaller tubercles. The secondary and miliary spines are very numerous, but are 

 much shorter than the primaries. The abactinal system is small (about .20 of the 

 diameter) and the two posterior ocular plates are in broad contact with the anal 

 system. Pedicellariae, particularly the globiferous ones, are very numerous, and 

 the tridentate are often two millimeters long, not including the stalk. 

 Station 4777- Petrel Bank, Bering Sea, 43-52 fathoms. 



" 4778. Petrel Bank, Bering Sea, 33-43 fathoms. 



" 4779. Petrel Bank, Bering Sea, 54-56 fathoms. 



" 4782. Off East Cape, Attu Island, Aleutians, 57-59 fathoms. 



" 4784. Off East Cape, Attu Island, Aleutians, 135 fathoms. 



