26 HAWAIIAN AND OTHER PACIFIC ECHINI. 



shorter and wider, about 36 by 21 mm. and about equally open at tip. Posterior 

 petals longer and wider, 41 by 22 mm., about equally open. Periproct close to 

 margin, about 5 mm. across, covered with numerous small, miliary bearing 

 plates. 



Primary spines of aboral surface, 2 or 3 mm. long, smooth, pointed, slightly 

 flattened and often distinctly larger below the tip, thus becoming somewhat 

 spatulate (PI. 122, figs. 17, IS) ; on oral surface, the primaries are thicker, blunter, 

 and longer, especially around the mouth (PL 122, fig. 16). Miliary spines long, 

 slender, and cylindrical or terete. Tridentate pedicellariae very common and 

 large (heads = 1-1.6 mm.) on oral surface but rare and small (heads = .25- 

 .75 mm.) aborally; the valves vary much in shape -svith their size. The small 

 pedicellariae have broad, nearly straight valves, coarsely serrate on margin 

 and meeting for nearly the full length of the blade; in larger ones, the valves 

 are narrow and compressed, finely serrate along distal half of blade, where they 

 meet; in the largest, the valves (PI. 123, figs. 2, 3) are curved, dentate on margin, 

 compressed and decidedly expanded at tip, where they meet. Ophicephalous 

 pedicellariae common aborally, wanting on oral side; heads about .5 mm. 

 long; opening of blade (PI. 123, fig. 4) broad and low, guarded by conspicuous 

 teeth. Triphyllous pedicellariae rare, or at any rate, xerj hard to find; \-alves 

 broad and flattened, about .07 mm. long, similar to those of rotundus (PL 123, 

 fig. 25). 



Color aborally, light reddish; test yellowish brown when cleaned of the 

 overlying red-brown skin; spines white or whitish, but with enough reddish 

 tmge to give, with the skin, a general hght reddish color; orally the skin is dull 

 greenish yellow, while the spines are pale brown, with a reddish tinge. These 

 are the colors of the holotype, dried after thirty years in alcohol ; the color in 

 life is not known. 



A second, smaller specimen is very similar but the colors are paler, the test 

 aborally is reddish and the primary tubercles are less numerous (4-6) on the 

 ridges between the pore-pairs of the unpaired petal. 



The holotype is from Blake St. 276, off Barbados, 94 fnis.; the smaller 

 specimen is from Blake St. 177, ofT Dominica, 118 fms. 



These specimens were labelled "£'. rosaceus" without critical examination, 

 and were never subsequently examined until after ]\Ir. Agassiz's death. When 

 compared with specimens of rosaceus of the same size, the differences are so 

 evident and seem to be so constant, I have not hesitated in considering this an 

 undescribed species. 



