Boone, Echinodermata, Cruises of "A7'a" and "Alva" 131 



frame, set well apart from one another, on the inner half of the 

 jaw frame. 



The first under arm plate is minute and in contact with the 

 outer angle of the adoral plate. A typical under arm plate is hexa- 

 gonal, longer than wide, with the outer margin widely convex, the 

 inner margin very narrow, and the lateral margins each consist- 

 ing of a short oblique proximal part and the longer concave por- 

 tion adjacent to the tentacle pore. There is one tentacle scale, 

 which forms a wide oval. 



The side arm plates each support six or seven short, thick, 

 blunt, rough arm spines, which are conical. One specimen has 

 only five to six arm spines, but otherwise agrees with the typical 

 savignyi. 



The upper arm plate is nearly twice as wide as long, with the 

 outer margin widely convex-sinuate, the dorsal surface continu- 

 ous reticulate with small, circular granules. 



References: Ophiolepis savignyi, Muller, J., and Troschel, 

 F. H., Syst. der Asteriden, 1842, p. 95.— Savigny, J. C, de, 

 Icon. Echinodermes, Descripte de I'Egypte, 1809, pi. 2, figs. 

 4,5. 



Ophiactis savignyi, Ljungman, A., Ofv. K. Vet. Akad. Forh. 

 Stockholm, 1866, Bd. XXIII, p. 323 ; Ibid., 1871, p. 627.— 

 Lyman, Th., Kept. Voy. H. M. S. "Challenger" Zool., Ophiu- 

 roidea, vol. V, 1882, p. 115; Marktanner-Tumeretscher, 

 Annal. Naturh. Hofmus. Wien, 1887, Bd. II, p. 296.— BROCK, 

 J., Zeitschur. f. Wiss. Zool. Berlin, 1888, Bd. XL VII, p. 482.— 

 Pfeffer, G., Mitteil. Naturh. Mus. Hamburg, Jahrg., Bd., 

 1896, Bd. XIII, p. 48.— LUDWIG, H., Mem. Couronn. Sav. 

 Acad. Belg., 1882, t. XLIV, p. 14 ; Abh. Senckenb. Nat. Ges. 

 Frankfurt, 1899, Bd. XXI, p. 545.— Lutken, Ch. and MoR- 

 TENSEN, Th., Mem. Mus. Comp. Zool., 1899, vol. XXIII, p. 

 140. — KOEHLER, R., Siboga Expeditie, Ophiures Littorales 

 Monogr. XLV-B, 1905, p. 26 ; in Michaelson, und Hartmeyer : 

 Die Fauna Sudwest-Australiens. Bd. I, lief. 5, 1907-08, p. 245 ; 

 Bull. LXXXIV, U. S. Nat. Mus., 1914, p. 41.— Matsumoto, H., 

 Journ. Coll. Sci. Imp. Univ. Japan, Tokio, 1917, vol. XXXVIII, 

 158.— Clark, H. L., Mem. Mus. Comp. Zool., 1915, vol. XXV, 

 p. 265, No. 768 ; Publ. 214, Carnegie Inst. Washington, papers 

 Marine Biol., 1921, vol. X, p. 108. 



