A MONOGRAPH OP THE EXISTING CRINOIDS 395 



In a revision of the family Mariametridae published in 1913 I suppressed the 

 family Pontiometridae, transferring the genus Epimetra to the Colobometridae and 

 Pontiometra to the Mariametridae. As here constituted the family Mariametridae 

 included the genera Pontiometra, Oxymetra, Liparometra, gen. nov., Lamprometra, 

 gen. nov., Dichrometra, and Mariametra. 



In the memoir on the unstalked crinoids of the Siboga expedition published in 

 1918 I recognized the family Stephanometridae, with the single genus Stephanometra, 

 and the family Mariametridae, with the genera just given. 



In the present work the family Mariametridae is considered as including, together 

 with the genera assigned to it in 1913 (except Pontiometra), the genus Stephanometra, 

 the family Stephanometridae being suppressed, and also the new genus Pelometra. 

 The genus Pontiometra is herein placed in the family Colobometridae. 



In his report upon the comatulids collected by the Challenger expedition Car- 

 penter placed all the species of the family Mariametridae known to him hi the Palmata 

 group, which in addition included Antedon manca, A. disciformis, and A. clemens, 

 the first two of which belong to the family Colobometridae, falling in the genus 

 Cyllome f ra, while the third belongs to the family Himerometridae, falling ha the genus 

 Heterometra. 



KEY TO THE GENERA OF THE FAMILY MARIAMETRIDAE 



a 1 . Cirri large and long, composed of more than 40 (usually of more than 50) segments (from the 

 Philippines southward to New Britain and the Kei Islands, and westward to Ceylon; 0-82 



meters) Oxymetra (p. 396) 



a 2 . Cirri of moderate length or short, composed of less than 40 segments. 



b 1 . One or more of the oral pinnules enlarged, greatly stiffened, sharp pointed, and spinelike; 

 division series well separated, the component ossicles with rounded ventrolateral exten- 

 sions (from Macclesfield Bank and Philippine Islands to Pelew, Caroline, and Marshall 

 Islands, Samoa, Fiji, the Tonga Islands, New Caledonia, Torres Strait, and Lesser Sunda 



Islands, and westward to Madagascar; 0-245 meters) Stephanometra (p. 407) 



b 1 . Enlarged lower pinnules tapering distally to a fine and usually (but not always) flexible point, 

 without spiniform tips; division series usually in lateral contact, the component ossicles 

 never with ventrolateral extensions. 

 c 1 . Genital pinnules with a narrow expansion on lower edges of segments (Amboina; about 91 



meters) Pelometra (p. 459) 



c 2 . No expansion of lower edge of segments of genital pinnules. 



d l . P 2 and P 3 slender, similar, and of same length (southern Japan from Hirado Strait to 

 Sagami Bay, Bonin Islands, and southward to Tonga Islands, Port Molle, Queensland 



Moluccas, and Lesser Sunda Islands; 0-69 meters) Liparometra (p. 460) 



d 1 . P 2 and P 3 unequal in length or stoutness, usually in both. 



e l . P2 longer and stouter than P 3 (from Hongkong and Philippines to Caroline, Marshall, 

 and Hawaiian Islands, Fiji, Tonga Islands, New Caledonia, the Solomon Islands, north- 

 ern Australia south to Cape Hillsborough, Queensland, and Abrolhos Islands and 

 possibly Perth, Western Australia, and westward to east coast of Africa from Red Sea 

 south to Dar-es-Salaam, Tanganyika Territory; 0-51 [?421] meters) 



Lamprometra (p. 472) 

 e 2 . P 3 longer and stouter than P 2 . 



/*. Lateral portions of dorsal surface of the division series smooth (from southern Japan, 

 from Korean Straits to Sagami Bay, to Hongkong, Philippines, Pelew and Ad- 

 miralty Islands, New Guinea, and Amboina, and westward to Madagascar and 

 east coast of Africa from Lamu, Kenya, southward to Durnford Point, Zululand; 

 0-164 meters) Dichrometra (p. 536) 



