236 bulletin: museum of comparative zoology. 



the diameter of the abactinal system is rather more than half the diameter of tlie 

 test, and the aual system is nearly three-fourths of the abactinal ; while in the 

 specimens of meijerei, the primary spines are bright green, the abactinal surface 

 tends to become deep purple, the diameter of the abactinal system about equals 

 one-half that of the test, and the aual system is about two-thirds of the abactinal. 

 The specimens of meijerei are on the whole much larger than those of nicoharicitm, 

 some of them being over 30 mm. in diameter. Tliey also come from more shallow 

 water, and only from the vicinity of Molokai and southern Oahu, as the following 

 list of stations shows. 



Station 3817. Off Diamond Head, Oahu, 320 fathoms. 



3818. Off Diamond Head, Oahu, 293-295 fathoms. 

 3836. Off Lae-o Ka Laau Light, Molokai, 238-255 fathoms. 

 3839. Off Lae-o Ka Laau Light, Molokai, 259-266 fathoms. 

 3865. Off Mokuhooniki Islet, Pailolo Channel, 256 fathoms. 

 3914. Off Diamond Head, Oahu, 289-292 fathoms. 

 3918. Off Diamond Head, Oahu, 257-294 fathoms. 

 " 3920. Off Diamond Head, Oahu, 265-280 fathoms. 

 " 4096. Off Mokuhooniki Islet, Pailolo Channel, 272-286 fathoms. 



4097. Off Mokuhooniki Islet, Pailolo Channel, 286 fathoms. 

 " 4105. Off Lae-o Ka Laau Light, Molokai, 314-335 fathoms, 

 4116. Off Kahuku Point, Oahu, 241-282 fathoms. 

 4122. Off Barber's Point Light, Oahu, 192-352 fathoms. 

 4178 (?). Off Kawahioa Point, Niihau, 319-378 fathoms. 

 The average depth of these stations is 280 fathoms, and there is no reason to 

 believe that any specimens of this species wei'e taken in more than 320 fathoms. 

 One hundred and forty-four specimens. 



DIADEMATIDAE Peters. 

 Diadema paucispinum A. Ao. 

 Diadema paucispinum A. Agassiz, 1863, Bull. M. C. Z., 1, p. 19. 



These specimens are certainly distinct from West Indian specimens and equally 

 so from mexicanum and savigni/i; it therefore seems advisable to recognize pauci- 

 spinum once more. 



Puako Bay, Hawaii. 



Honolulu. 



Station 3968. French Frigate Shoal, 14?t-161 fathoms 

 " 4169. Off Modu Manu, 21-22 fathoms. 



Nine specimens. 



Echinothrix calamaris A. Ag. 



Echinus calamaris Pallas, 1774. Spic. Zool. 1, fasc. 10, p. .31 ; Plate 2, Figs. 4-8. 

 Echinothrix cala7na)is A. Agassiz, 1872, Rev. Ech. Pt. 1, p. 119. 



Only young specimens were collected, the largest being 30 mm. in diameter. 

 Puako Bay, Hawaii. 



