J42 BULLETIN 70, UNITED STATES NATIONAL MUSEUM. 



spiiios. A very few pectinate pcdiccllariic, with ten or twelve short, bhint, slender 

 p!i])illa>, occur irrejjuhirly on three rays between the first and second or second 

 and third inferomarginals, and three of the actinal interradial areas have one or 

 two similar pedicellarije. The actinal mtermediate plates are very few (five to 

 seven, and fifth adambulacral abuts against second inferomarguial), and are naked 

 except for one to three prominent spines or spinules on each plate. 



Adambulacral plates, with proximally one, two, and, distally, three unequal 

 tapering furrow spinules, and on the actmal surface, two much longer, slender 

 blunt spines about two and one-third or two and one-half times width of plate. 

 That nearest margin is slenderer and slightly shorter and often stands at the aboral 

 inner corner of [)late, fairly on margin. 



Mouth ])lates with a less extensive furrow margin than species of Nearchaster; 

 furrow spinules five or six graduated from a long inner tooth to a very short outer 

 spinelet. About five tapering sharp spines stand on the surface in an angular series. 



Madreporic body fairly large convex situated its own diameter from margin 

 and surrounded by four prominent spines. Striae fine, radiating from center. 



Color in life, above pinkish buff, grayish at base of ray on papular area; actinal 

 surface, Naples yellow; tube feet, pinkish. 



Porsal muscle bands much stouter and broader than in Nearchaster, and more 

 as in L. dawsoni, but not so tliick as in that form. After the proximal ninth of 

 ray the muscle becomes evident and runs parallel with the margin, being about 1.5 

 imn. wiilc. On tlie outer third of ray it joins its fellow and the entire width of the 

 narrow dorsal integument is covered with muscle. In N. aciculosus the bands are 

 thin enough to be translucent. This muscle is not attached to a proximal ambu- 

 lacral ossicle, as in L. dawsoni. 



Type.— C&t. No. 27802, U.S.N.M. 



Type-locality. — Albatross station 4530, Monterey Bay, California, 958 to 755 

 fathoms, very soft mud, one specimen, Albatross, 1904. 



Distrihution. — Known only from type-locality. 



Genus BENTHOPECTEN Verrill. 



Benihopecten Verrill, Amer. Journ. Sci. and Arts, vol. 28, September, 1884, p. 218 (footnote). 



Type, B. spinosus Verrill. 

 Pararchasler Sladbn, Narr. Challenger Exp., vol. 1, 1885, p. 610, fig. 204. Type, P. pediei/er 

 Sladen; figure. 



Diagnosis. — Benthopectiniihc with odd mterradial marginal plates and rather 

 flat immersed abactinal j>lates without definite arrangement and bearing single 

 spines or groups; usually enlarged spines on di.sk; no paxillse; papulae confined to 

 disk and base of ray, exceptionally extending to middle of ray. Rays very long, 

 tapering, and flexible; disk small. Marginal plates suboval or triangular, elongate in 

 the direction of ray, and confined strictly to margin, the two series not exactly o])po- 

 site ; each plate with a prominent boss. Superomarginal plates with usually one 

 long cyhndrical tapering spine, and stmietimes a companion; inferoniarginal plates 

 with one or more similar spines (in one species clavate) ; general surface of plates of 

 both series naked, or only with minute isolated spiniferous thomlets. Odd supero- 



