AGASSIZ AND CLARK: REPORT ON ECHINI. 243 



Orechinus monolini Dod. 

 Trigonocidaris monolini A. Agassiz, 1879. Proc. Amer. Acad., 14, p. 203. 

 Orechinus monolini Doderlein, 1905. Zool. Anz., 28, p. 622. 



An excellent series of this rare and interesting species was taken by the "Alba- 

 tross." It is notable for the large size of many of the specimens, which range 

 from 6 to 22 mm. in diameter. 



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



3865. Off Mokuhooniki Islet, Pailolo Channel, 256-283 fathoms. 

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

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

 4085. Off Puniawa Point, Maui, 267-283 fathoms. 

 4117- Off Kahuku Point, Oahu, 253-282 fathoms. 



4125. Off Kahuku Point, Oahu, 963-1124 fathoms. 



4126. Off Kahuku Point, Oahu, 743-1278 fathoms. 

 " 4131. Off Hanamaulu, Kauai, 257-309 fathoms. 



Twenty-nine specimens. 



Prionechinus chuni Dod. 

 Prionechinus chuni Doderlein, 1906. Ech. Deuts. Tiefsee Exp., p. 192 ; Plate 24, Fig. 3. 



A small, but very good, series of this interesting little urchin, ranging from 2.5 

 to 11 mm. in diameter, was taken at the following station. Doderlein's admi- 

 rable description, coupled with the photographs he gives, leaves no doubt as to the 

 identity of these specimens. 



Station 4126. Off Kahuku Point, Oahu, 743-1278 fathoms. 



Seven specimens. 



Prionechinus sculptus A. Ag. and Clark. 



This species is distinguished from the four previously known species of the 

 genus, as limited by Doderlein (1906), by the very small and distinct buccal 

 plates, with five pairs of buccal feet, the smooth, longitudinally striated primary 

 spines, and the handsomely sculptured and ornamented abactinal system. The 

 genital opening is near the centre of the plate. The test is not so high as in the 

 preceding species and the anal plates, are much less numerous, with one evidently 

 larger than the rest. The color is dull purplish-red, very pale in the smaller 

 specimens. The primaries are white, but the longitudinal striations are purplish. 

 The specimens range from 2 to 10 mm. in diameter. 



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

 4028. Off Ukula Point, Kauai, 444-478 fathoms. 

 " 4039. Off Kawaihae Light, Hawaii, 670-697 fathoms. 



4083. Off Puniawa Point, Maui, 238-253 fathoms. 

 " 4086. Off Puniawa Point, Maui, 283-308 fathoms. 



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

 " 4088. Off Mokuhooniki Islet, Pailolo Channel, 297-306 fathoms. 

 " 4115. Off Kahuku Point, Oahu, 195-241 fathoms. 

 Sixty-seven specimens. 



