126 Clark — New Genera of Unstalked Crinoids. 



in Charitometra, should have been referred to Thalassometra ; the 

 Antedon flava of Koehler and the Antedon porrecta of Carpenter 

 (which were omitted) also belong to Thalassometra. I had not 

 been able to consult Professor Bell's paper on South African 

 crinoids, although I had examined specimens of his capensis ; 

 of the two other species described, sclateri belongs to the genus 

 Charitometra (near C. insequalis) and magnlcirra to Thalassometra. 



Family HIMEROMETRULE. 

 Oligometra gen. nov. 



Genotype. — Antedon serripinna P. H. Carpenter, 1881. 



Centro-dorsal flat, discoidal, the cirri marginal, in one or two more or 

 less irregular and crowded rows. Cirri short and stout, composed of 

 few, twenty or less (rarely one or two more), squarish or short joints; 

 the opposing spine central in position and short; the distal joints may 

 bear centrally situated spines, paired spines, or tubercles. Radials more 

 or less concealed; costals rounded, broad, and may or may not he in 

 apposition laterally. Ten arms of rather short, wed<je-shaped joints, 

 becoming oblong distally. Proximal pinnules rather stouter and stiffer 

 than the others, hut not especially marked; one or more elongate, hut 

 little, if any, longer than the distal pinnules; the proximal joints of the 

 lower pinnules often bear strong, thin, rounded keels, or elongate pro- 

 cesses, and the distal joints may have overlapping and spiny distal ends. 



Color. — Purple or yellow, or yellow or white, more or less heavily 

 banded or mottled with purple. 



Geographic distribution. — Tropical; Caribbean Sea at Panama; east 

 Africa eastward to northern Australia and southern Japan. 



Depth. — Littoral, but occurring down to 60 fathoms. 



The short, stout cirri, with short or squarish suhequal joints bearing 

 dorsal spines or tubercles, and the opposing spine in the center, and the 

 round and stiffened, hut otherwise not specially differentiated, lower 

 pinnules distinguish this genus at a glance. The included species are, 



0. adeonse (Lamarck). 0. japonica (Hartlaub). 



0. indent (Pell). 0. pinniformis (P. H. Carpenter). 



0. caribbea A. II. Clark. 0. serripinna (P. II. Carpenter). 



0. carpenteri ( Pell). 



Family ANTEDONID.K. 



Erythrometra gen. nov. 



Genotype. — Antedon ruber A. II. Clark, 1907. 



Radial laces low, about as broad as high; the dorsal surface of the 

 radials is approximally vertical to the dorso-ventral axis of the animal; 

 muscular Fossae small, their area scarcely greater than that of the inter- 

 articular ligament fossa', the notch separating them broad, hut compara- 

 tively shallow, not reaching half way to the axial canal. Centro-dorsal 



