CLARK! CRINOID FAMILY ANTEDONIDAE 131 



Phrixometra, gen. nov. 



Genotype. — Antedon longipinna P. H. Carpenter, 1888. 



Diagnosis. — The centrodorsal is rounded conical or hemispherical, 

 not so high as broad at the base; the cirri are about XXX, 20-25; 

 the proximal cirrus segments are elongated, at least twice as long as 

 the median diameter and usually much longer; the brachials do not 

 have strongly produced and very spinous distal ends ; at most the distal 

 edges of the outer brachials are bordered with fine spines; the pinnules 

 are very long, the proximal longer than the distal; P 2 is very slightly 

 shorter than P x , but similar to it, with about 18 elongated segments; 

 the following pinnules are similar; the arms are about 20 mm. long. 



Geographical Range. — Southeastern South America. 



Bathy metrical Range. — Known only from 1080 meters. 



Included Species. — Phrixometra longipinna (P. H. Carpenter). 



