Boone, Echinodermata, Cruises of "Ara" and "Alva" 117 



forceps-like pedicellariae, located on the papular areas, these vari- 

 ously having the jaw^s subequal in length or from 1.5, 2, or 2.2 

 times the height of the surrounding granules. These granules of 

 the papular areas are variously rounded, convex, or subconic. 



The adambulacral armature (somewhat imperfect in the pres- 

 ent specimen) has seven to nine furrow spines where uninjured. 

 The subambulacral spines are two or three, heavy, with blunted 

 apices. External to these is a second series of smaller, shorter 

 spines of two, and more frequently three, per series. The elongate 

 bivalve, slit-like pedicellariae are quite numerous in the area adja- 

 cent to the jaw-angle. 



In the second specimen, "B" (plates 35 and 36), there are 

 respectively 9, 11, 11, 10 and 10 primary radial tubercles on the 

 carinal ridges of the five rays, with a cluster of three not quite so 

 large "acorn" tubercles in the center and eight tubercles each in 

 three interradial areas, seven tubercles in the fourth and ten in 

 the fifth interradial area. The superomarginal spines are highly 

 developed, being present in almost continuous series along the 

 brachial and interbrachial margins, those of the interbrachial 

 margin being the largest. The inferomarginal spines are quite 

 large, six to eight present in each interbrachial area and a few 

 large spines present near the tips of each ray. 



References: Pentaceros alveolatus, Perkier, E., Archiv. Zool. 

 Exper. et Gen., Paris, 1875, t. V. p. 75. — Koehler, R., Echino- 

 derms of the Indian Museum, Pt. VI, Asteroidea II, An Ac- 

 count of the Shallow-Water Asteroidea, 1910, p. 95, pi. 10, 

 fig. 1, pi. 14, fig. 8 (shows Perrier's type). 



Oreaster alveolatus, Bell, F. J., Proc. Zool. Soc, London, 1884, 

 p. 73.— Fisher, W. K., Bull. 100, U. S. Nat. Mus., 1919, vol. 

 Ill, p. 341, pi. 101, fig. 1. 



Pentaceraster alveolatus, Doderlein, L., Zool, Jahrb. Syst., 1916, 

 Bd. XL, p. 428, figs. K and L ; Siboga-Expeditie, Die Aster- 

 iden III, Oreastinae, p. 332, pi. 34, figs. 1-11, pi. 25, figs. 1-7, 

 pi. 29, fig. 10. (Dr. Doderlein considers Pentaceros novae- 

 caledoniae Koehler, loc. cit. 1910, p. 104, pi. 13, fig. 6, pi. 15, 

 figs. 3 and 4, from New Caledonia, and Pentaceros bedoti, 

 Koehler, R., Revue Suisse Zool., 1911, t. XIX, p. 1, pi. 1, 

 fig. 1, from New Britain, synonyms of P. alveolatus (Perrier) . 



