CLARK: THE CIDAIUDAE. 211 



specimens of the two species are very difficult to distinguish. The others are 

 labelled " Dorocidaris papillata," which is what one would naturally call them, if 

 rugosa is not to be recognized as valid. 



CALOCIDARIS, gen. nov. (Greek, k<x\6s, beautiful, + cidaris). 



Test large and rather high ; coronal plates 7 or 8 ; areolae distinct and con- 

 siderably sunken, the most actinal tending to merge together vertically ; median 

 interambulacral area not at all sunken, covered with numerous miliaries and with 

 more or less horizontal grooves or narrow furrows, such as occur in Temnoeidaris; 

 ambulacra about .25 of interambulaera in width ; poriferous zones scarcely at all 

 sunken ; median ambulaeral area very wide, about .55 of ambulacrum, with very 

 few tubercles aside from the customary double marginal series; pores oblique, 

 large and close together. Abactinal system not quite .50 h. d., of very irregular 

 outline ; ocular plates deeply notched by ambulacra. Actinostome very small, 

 only about .65 of abactinal system. Primary spines 3 h. d., cylindrical, white, 

 smooth, and polished like porcelain, more or less tinged with pink and green ; 

 actinal primaries flat and longitudinally fluted, but not notched or serrate. Sec- 

 ondaries flat and tapering, many bluntly pointed. Pedicellariae as in Dorocidaris. 



Although in many respects like Dorocidaris, the very broad and nearly bare 

 median ambulaeral areas, the remarkable color, and especially the smooth, pol- 

 ished primaries, mark this genus at a glance. The largest primaries are all broken 

 in the specimen in the Musum of Comparative Zoology, so that their length is 

 not shown in the figure given. But a specimen in the U. S. National Museum, 

 which is the most beautiful echinoid I have ever seen, is nearly perfect. The 

 primaries are 160 mm. long, rather more than 3 times the diameter of the test, 

 and scarcely taper at all, but are cylindrical throughout their entire length. The 

 genus is monotypic and very few specimens are known. The above descrip- 

 tion is based on a specimen 61 mm. h. d., from near Barbados, but two other 

 specimens in the U. S. National Museum have been examined. 



Calocidaris micans. 



Dorocidaris micans Mortensen, 1903, Ingolf-Exp. Eeh., p. 23. 



Plate 3. 



This is easily the handsomest, as well as one of the largest, of the West Indian 

 cidaroids. It reaches a diameter of more than 60 mm. The test is white, and 

 the secondaries nearly so, but the abactinal system and adjoining coronal plates 

 are pale green ; the primaries when dry are shining white, with a pink base and 

 occasional faint, irregular marks of the same color ; they look as though artiGcially 

 polished. In alcoholic specimens the spines have a greenish shade and the pink 

 is deeper. The only known specimens of this beautiful species were taken by 

 the " Albatross " off the northwestern coast of Cuba in 205 fths., and by the 

 " Blake" off Barbados in 125 fths. 





