AGASSIZ AND CLARK \ REPORT ON ECHINI. 135 



BRISSINA Gray. 

 Hemiaster gibbosus A. Ac 

 Hemiaster gibbosus A. Agassiz, 1879. Proc. Araer. Acatl., 14, p. 210. 

 The large series collected range in size from 10 to 34 mm. long diameter, and 

 many of them seem to be almost spherical. 



Station 4913. Southwest of Koshika Islands, Japan, 391 fathoms. 

 " 4907. Between Kobe and Yokohama, Japan, 244-253 fathoms. 

 " 496S. Between Kobe and Yokohama, Japan, 253 fathoms. 

 " 4970. Between Kobe and Yokohama, Japan, 500-649 fathoms. 

 " 4971. Between Kobe and Yokohama, Japan, 649 fathoms. 

 " 4973. Between Kobe and Yokohama, Japan, 600 fathoms. 

 " 4977. Between Kobe and Yokohama, Japan, 544 fathoms. 

 " 5053. Suruga Gulf, Japan, 503 fathoms. 

 " 5054. Suruga Gulf, Japan, 282 fathoms. 

 " 5056. Suruga Gulf, Japan, 258 fathoms. 

 5083. Off Omai Saki Light, 624 fathoms. 

 " 5086. Sagami Bay, Hondo, Japan, 292 fathoms. 

 " 5087. Sagami Bay, Hondo, Japan, 614 fathoms. 

 " 508S. Sagami Bay, Hondo, Japan, 369-405 fathoms. 

 " 5093. Off Gulf of Tokyo, Japan, 302 fathoms. 

 Fifty-five specimens. 



Hemiaster globulus A. Ag. and Clark. 



The largest Hemiaster collected differs so much from the large specimens of 

 gibbosus that we consider it an undescribed species. The test is nearly globular, 

 measuring 36 mm. in length, 35 mm. in width and 33 mm. in height. The pos- 

 terior end is vertically truncate, while the plastron forms a broad rounded keel. 

 The most striking character, however, is the narrowness of the petals and the 

 length of the posterior pair. In gibbosus, the posterior petals are about three- 

 fifths of the length of the lateral ones, while their width is about three-fourths of 

 their own length. In globulus, the posterior petals are seven-tenths of the length 

 of the lateral ones, and their width is less than half their own length. In all the 

 specimens of the large series of gibbosus no connecting links between the two forms 

 were found. The test is more thickly covered with tubercles and small spines in 

 globulus than in gibbosus, but the color is not essentially different. 



Station 4832. Between Nanao and Tsuruga, Hondo, Japan, 76-79 fathoms. 



One specimen. 



Brissopsis luzonica A. Ag. 



Kleinia luzonica Gray, 1851. Ann. Mag. Nat. Hist., (2) 1, p. 133. 

 Brissopsis luzonica A. Agassiz, 1872. Rev. Ecli., Pt. 1, p. 95. 



There are only a few specimens of this species but they are mostly well 

 preserved. 



