176 Clark — New Genera of Unstalked CriuoifJs. 



Stephanometrinie sub-lain. nov. 



Tlic lirachials arc of moderate length, wedge-shaped; at least one of 

 the i»roxinial pinnules is very stiff, sliarp-pointed, and spine-like, with 

 comparatively few segments; the division series and first two brachials 

 have lateral projections, and are well separated; second division series 

 are always itrcscnt, and, likt' all the other division series, of two compo- 

 nents. 



Included genera. — Oxymetra ; Stephanomctra. 



Mariametrinse sub-fain. nov. 



The l)rachials and division series are as in the Ste]ihanoinetrin<T, but 

 the division series are in close lateral apposition, without lateral processes; 

 the elongate ])roximal pinnules are enlarged, but are Hagellate, at least 

 distally, and have conijaaratively numerous segments. 



Included genera. — Mariamrtra ; DIchromrtra. 



The family Antedonidte falls naturally into six sub-families, as follows: 

 Antedoninse sub-fam. nov. 



The few cirri are short, witli few segments, irregularly disjiosed on a 

 low-hemispherical centro-dorsal ; an opposing spine is i)resent on the 

 penultimate cirrus segment. 



Included gi'iiera. — Aiitcdou; Masfigomcfia; Compsometra ; Iridonietra. 



Perometrinse suli-fam. nov. 



One or more of the lower pinnules is absent; the cirri, which have 

 numerous segments, shorter distally than proximally, are numerous, and 

 are evenly distriliutcd, closely crowded, on a hemispiierieal or uiore or 

 le.ss conical centro-dorsal. 



Included genera. — Perometra; Erythrometra; Hypalometra. 



Zenometrinse sub-fam. nov. 



The cirri, whicli arc loiigwitli numerous segments, are arranged in dcli- 

 nitc coluums, usually well sc])ara(ed, at least laterally, on a more or less 

 elongate conical centro-dorsal to which they are weakly attached ; some 

 of tlu' lower pinnules may be absent. 



Includ('<I genera. — Zmomrti-a; Psalliyroxtctm; Ijcplo)H(ira; AdrhDnetra; 

 BnhiixiDirtra. 



Heliometrinas sub-fam. nov. 



The numerous cirri, whicli are slender to moderately stout, have numer- 

 ous segments which are much shorter distally than j)roximally, and are 

 evenly distributed over and closely crowded on a large lieniisi)herical or 

 rounded conical centro-dorsal; all the pinnules are jiresent. 



Included genera. — Promachocrinus ; lleliomelra; Trichometra; Ilaihro- 

 metra; Isomelra. 



Thysanometrinae sub-fam. nov. 

 The first jiinnnle is coin|iosed of numerous srpiarisb or round segments, 

 but in one genus is much reduced in length; the following |(inniiles are 



