Boone, Echinodermata, Cruises of "Eagle" and "Am," 1921-28 141 



elongated, consisting of three slender valves, each with a small base 

 and an attenuated tongue-like distal portion, the margin of which is 

 crenulate. 



A third type of pedicellariae, the trifoliate, is also found abun- 

 dantly on the actinostome, outside the principal ring of gemmiform 

 pedicellariae and also is found abundantly scattered among the spines 

 on the test. Each has an exceedingly long, slender stem, approxi- 

 mately the distal half of which is flexible, the head composed of three 

 valves, each of which is convex outwardly, nearly subcircular, with 

 the distal margin a bit flattish, crenulate. (Fig. C.) 

 References: Echinus lucunter Linne, Syst. Nat. ed. 10, p. 665, 



1758. 

 Echinometra lucunter Desmoulins, C. k., Etudes sur les Echinides, 

 p. 260, 1835-37 (with synonymy, partim.). — Loven, Bih. Svensk. 

 Vet.-Akad. Handl., vol. 13 (4), no. 5, p. 157, 1887.— Mortensen, 

 Th., Studies Devel. and Larval Forms Echinod., p. 71, pi. 1, 

 figs. 1-2, pi. 12, fig. 1, 1921. — H. L. Clark, Univ. Iowa Studies 

 Nat. Hist., vol. 9, p. 118, 1921; Cat. Recent Sea Urchins, Brit. 

 Mus., p. 143, 1925. — Boone, L., Bull. Bingham Oceanog. Coll., 

 vol. I, art. 4, p. 221, 1928. 

 Cidaris lucunter Leske, Klein Addit. Echinod., p. 109, tab. IV, 



C, D, 1778 (part). 

 Cidaris subangidaris Leske, ibid, p. 106, tab. Ill, C, D, 1778. 

 Echinometra subangularis Desmoulin, op. cit., p. 266, 1835, part. — 

 A. Agassiz, Mem. Mus. Comp. Zool., vol. Ill, part I, p. 283, 

 pi. X, a, figs. 2, 3, 4, 1872.— H. L. Clark, Rept. U. S. Fish Comm., 

 vol. XX, part 2, p. 253, 1901. — A. E. Verrill, Trans. Conn. 

 Acad. Arts and Sci., vol. XIII, p. 324, pi. 34A, fig. 2, 1904-07.— 

 Tennant, D. H., Gardner, M. S., and Smith, D. E., Papers from 

 Tortugas Laboratory of Carnegie Institution of Washington, 

 vol. XXVII, pp. 1 to 46, 7 plates ; pp. 47-52, 6 plates, 1931. 



Suborder : Clypeastrina. 



Family: CLYPEASTRIDAE. 



Genus: CLYPEASTER Lamarck. 

 Clypeaster ravenelii (A. Agassiz). 



Plate 92. 



Type: Agassiz founded the species on a small specimen dredged 

 off Florida in 34 fms., by Count Pourtales and deposited in the 

 Museum of Comparative Zoology, and a much larger specimen 



