Thysanometrinae AH Clark 1909

A subfamily of Antedonidae in which the centrodorsal is usually hemispherical, rarely subconical or almost discoidal, with the cirrus sockets irregulary arranged in crowded transverse rows and a relatively large bare polar area; the cirrri are delicate, of very varible length, with the distal segments entirely without dorsal processes except for the occasional occurrence of a small opposing spine; the IBr series and arm bases make a very wide angle with the dorsoventral axis; P1 is long and flagellate, usually very flexible, composed of 30 to 40 segments, which are mostly or almost entirely about as long as broad with the corners cut away; P2 is of the same length as, or slightly shorter than, P1, but is usually composed of only helf as many segments or even fewer, most of which are much elongated, and the following pinnules resemble P2. The segments of the genital pinnules are never expanded.