138 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Between Hakodate and Yokohama, Japan, 182 fathoms. 

 Between Hakodate and Yokohama, Japan, 399 fathoms. 

 Suruga Gulf, Japan, 503 fathoms. 

 Suruga Gulf, Japan, 282 fathoms. 

 Suruga Gulf, Japan, 124 fathoms. 

 Suruga Gulf, Japan, 258 fathoms. 

 Suruga Gulf, Japan, 197-297 fathoms. 

 Suruga Gulf, Japan, 293 fathoms. 

 Suruga Gulf, Japan, 143-284 fathoms. 

 Sagami Bay, Hondo, Japan, 614 fathoms. 

 Sagami Bay, Hondo, Japan, 369-405 fathoms. 

 Off Gulf of Tokyo, Japan, 197 fathoms. 

 Off Gulf of Tokyo, Japan, 70 fathoms. 

 Off Gulf of Tokyo, Japan, 302 fathoms. 

 Two hundred and seventy-five specimens. 



Periaster rotundus A. Ac. and Clark. 



This species is extraordinarily like limicola from the Gulf of Mexico, as it has 

 two genital pores and the general shape of the test is of that species. The posterior 

 petals are shorter in rotundus (just one-half the lateral ones, instead of nearly two- 

 thirds as in limicola) and have fewer pairs of pores relatively (less than 65 per cent 

 of the number in the lateral petals instead of over 75 per cent as in limicola). The 

 mouth is nearer the centre of the actinal surface in rotundus (two-fifths of the long 

 axis from the anterior end, instead of one-third as in limicola). The test is 37 mm. 

 long, 35 mm. wide, and 31 mm. high. The color of the test is pale brown, and the 

 numerous spines are silvery-white (dry). 



Station 4946. Between Kagoshima and Kobe, Japan, 39 fathoms. 



One specimen. 



Periaster fragilis A. Ag. and Clark. 



The specimen upon which this species is based is obviously immature, and has 

 no genital openings. At first sight it might be mistaken for a young Schizaster ; 

 but comparison with specimens of S.japonicus and S. ventricosus of the same size 

 and smaller shows at once that such is not the case. In young Schizasters the 

 area occupied by the petals and peripctalous fasciole covers most of the abactiual 

 surface, the abactiual system is far back of the center, and the anterior ambu- 

 lacral furrow is already deep. None of these characters are found in the specimen 

 under discussion. That it is not the young of the preceding species is shown by 

 the extraordinary shortness of the posterior petals, the narrower, flatter test, and 

 the character of the actinostome. The test is 16 mm. long, 14 mm. wide, and 

 10 mm. high. The lateral petals are 5.3 mm. long and have 18 pairs of pores, 



