142 BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



AMPHIURA CARCHARA, new species.a 



Disk 8 mm. in diameter; arms about 35 mm. long. Disk covered 

 by numerous (250 to 300) scales. Radial shields long and narrow, 

 separated throughout or in contact distally . Upper arm plates more or 

 less pentagonal or hexagonal, decidedly rounded distally, in contact at 

 least to some extent on basal half of arm. Interbrachial spaces below 

 naked, save near margin, where the scaling ends abruptly. Oral 

 shields, roimded pentagonal, rather w^der than long. Adoral plates 

 narrow within but broader at outer end, not in contact with each other 

 at either end. Oral papillae two on a side, one rounded knob-like, at 

 apex of jaw, and one, which is long and spiniform, in outer corner of 

 mouth angle. Genital slits large. First under arm plate very small, 

 pentagonal; succeeding plates squarish or pentagonal, slightly in 

 contact with each other basally. Side arm plates large, meeting 



Fig. 55.— Amphiura carchara. 



(i. a, FROM above; 6, from below; c, side view of three arm 



JOINTS NEAR DISK. 



above and below except on basal part of arm, where they are slightly 

 separated; each plate carries three subequal arm spines about equal 

 to a joint. Tentacle scale single and small. Color (dried from alco- 

 hol) , pale gray or nearly white, except interbrachial spaces below which" 

 are brownish-3^ellow. 



Localities. — Albatross station 2854, off Alaska, lat. 56° 55' N.; long. 

 153° 4' W., 60 fathoms, black sand, bottom temperature 42.8°, 4 

 specimens; station 3069, off Washington, lat. 47° 25' 30" N.; long. 

 125° 42' W., 760 fathoms, green mud, bottom temperature 37.6°, 1 

 specimen; station 3338, off Alaska, lat. 54° 19' N.; long. 159° 40' W., 

 625 fathoms, green mud, sand, bottom temperature 37.3°, 6 speci- 

 mens; station 3340, off Alaska, lat. 55° 26' N.; long. 155° 26' W., 695 



o KapX'^P"^' signifying sharp-pointed, in reference to the peculiar oral papillae. 



