AGASSIZ AND CLARK: REPORT ON ECHINI. 239 



from anal system ; other oculars narrowly in contact with the single series of large 

 anal plates. Genital openings of only moderate size. Anal papilla conspicuous. 

 Actinostome somewhat larger than abactinal system; actinal cuts slight. Buccal 

 membrane closely covered with plates as in young Diadema. Primaries delicate, 

 glassy, slightly curved, blunt, with 5-7 prominent ridges, bearing few scattered, 

 very slender teeth, about equal to half the diameter of the test ; those of the am- 

 bulacra scarcely shorter or more slender than the others. 



Leptodiadema purpureum A. Ag. and Clark. 



The single specimen is only 9 mm. in diameter. The color is dull purplish, 

 becoming bright purple on the buccal membrane. The spines are nearly colorless. 

 Station 3847. Off Lae-o Ka Laau Light, Molokai, 23-24 fathoms. 



ECHINOTHURIDAB Wtv. Thoms. 

 Phormosoma bursarium A. Ag. 



Phormosoma bursarium A. Agassiz, 1881. Rep. Chall. Ech. p. 99 ; Plate 10 b. 



An excellent series of this species, ranging from 23 to 110 mm. in diameter, 

 was taken at the following stations. 



Station 3884. Pailolo Channel, between Maui and Molokai, 2S4-290 fathoms. 



3892. Off Mokapu Islet, N. coast of Molokai, 328-414 fathoms. 



3904. Off Mokapu Islet, N. coast of Molokai, 295 fathoms. 



" 3957. Off Laysan Island, 173-220 fathoms. 



3988. Off Hanamaulu, Kauai, 165-469 fathoms. 



3994. Off Mokuaeae Islet, Kauai, 330-382 fathoms. 



" 3997. Off Ukula Point, Kauai, 418-429 fathoms. 



4019. Off Hanamaulu, Kauai, 409-550 fathoms. 



4022. Off Hanamaulu, Kauai, 374-399 fathoms. 



4025. Off Mokuaeae Point, Kauai, 275-368 fathoms. 



4087. Off Mokuhooniki Islet, Pailolo Channel, 306-308 fathoms. 



4089. Off Mokuhooniki Islet, Pailolo Channel, 297-304 fathoms. 



4091. Off Mokuhooniki Islet, Pailolo Channel, 306-308 fathoms. 



4110. Off Lae-o Ka Laau Light, Molokai, 449-460 fathoms. 



" 4111. Off Lae-o Ka Laau Light, Molokai, 460-470 fathoms. 



4112. Off Lae-o Ka Laau Light, Molokai, 433-447 fathoms. 



4113. Off Lae-o Ka Laau Light, Molokai, 395-433 fathoms. 

 4141. Off Hanamaulu, Kauai, 437-632 fathoms. 



One hundred and fifty-four specimens. 



Sperosoma obscurum A. Ag. and Clark. 



The large series of Sperosomas collected cannot be referred to any of the previ- 

 ously known species. The coloration is somewhat variable, for while most of the 

 specimens are more or less decidedly violet or purple, some large ones are dis- 

 tinctly gray or yellowish-brown. The plates are not outlined in white (as in the 



