Boone, Echinodermata, Cruises of "Ara" and "Alva" 165 



There are two tentacle scales which together form a wide 

 oval, set obliquely to the arm length. This oval is slightly wider 

 at the distal end, the greatest width being about 55 percentum of 

 the length. 



The side arm plates extend well upon the ventral surface of 

 the arm for approximately one-third of its width. The side arm 

 plate bears four small conical spines, each of which is short, thick, 

 conical, flattish. These are arranged in close-set series and are 

 each about one-third as long as the adjacent plate. In addition to 

 these spines there is one small supplementary plate in the angle 

 between the tentacle scales and side and ventral plates. On the 

 dorsal there is a triangulate plate at the upper distal angle of the 

 dorsal arm plate, adjacent to and apparently partially fused with 

 the side arm plate. Viewed dorsally, the free margin of the side 

 arm plate has the contour of a wide arc, the upper end of which 

 is posterior, extending back to the inner margin of the dorsal 

 arm plate. 



The dorsal arm plate is much wider than long and has the 

 distal and proximal margins subparallel, the distal margin being 

 widely rounded at the outer ends and confluent with the oblique 

 lateral margins, which are directed inward posteriorly. The distal 

 margin of each dorsal plate is bordered by a linear series of small 

 scales, at either end of which there is a small triangular scale. 

 The dorsal and side arm plates have their surfaces paved with 

 microscopic, low, rounded granules. 



References: Ophiolepis cincta, Muller, J., and Troschel, F., 

 Syst. der Asteriden, 1842, p. 90. — Peters, W., Bericht Verhan. 

 k. Preuss. Akad. d. Wiss., Berlin, 1851, Bd. p. 466 ; Archiv. 

 f. Naturg., 1852, Jahrg. I, S. 86. — Lutken, Ch., K. Danske 

 Vidensk. Selskab. Skrifter. Naturg. og. Math. Afhandl. 5 E, 

 R. V, 1861, p. 203, pi. 2, figs. 6 a, b.— Lyman, Th., Mem. 

 Mus. Comp. Zool., 1865, vol. I, p. 60. — Ljungman, A., Ofv. 

 K. Vetensk., Akad. Forh., 1866, art. 9, p. 306.— VON Mar- 

 tens, H., in von Decken, Reisen in Ost-Af rica, 1869, Bd. Ill, 

 p. 129; Archiv. f. Naturg. Jahrg., XXXVI, 1870, s. 245.— 

 Gray, E., Ann. and Mag. Nat. Hist., 1872, ser. 4, vol. X, 

 p. 117. — Lyman, Th., Preliminary List of Living Ophiuridae 

 and Astrophytidae, 1880, p. 4; Rept. Sci. Res. H.M.S. ''Chal- 

 lenger," Zool., 1882, vol. V, Ophiuroidea, p. 19, pi. 37, figs. 7-9. 



