282 



BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



slightly convex granules. Radial shields completely covered, but 

 their presence indicated by five pairs of conspicuous ridges, extend- 

 ing from arm bases to center of disk. Margin of disk formed by a 

 calcareous thickening which bears large granules like those on radia 

 shields. None of the granules are conical or spine-bearing. Upper 

 surface of arm covered by alternating, but not clearly defined, bands 

 of smooth and hook-bearing granules ; smooth granules not crowded, 

 scattered; hook-bearing granules more regularly arranged in two 

 rather crowded series. Whole oral surface covered by granule- 

 bearing skin, with granules thickest on interbrachial spaces. Gen- 

 ital slits moderate, with a large genital scale along distal half of inner 

 margin. A single oral shield (madreporite) can be distinguished. 

 Adoral and oral plates usually skin covered. Teeth and tooth pa- 

 pillae rather numerous, longer and more spiniform than the few 

 scattered oral papilla?. Under arm plates distinguishable on basal 



FIG. 143. ASTROCHELE L.vis. x; 2.5. a, FROM ABOVE; 6, FROM BELOW; c, SIDE VIEW OF THREE ARM 



JOINTS NEAR DISK. 



joints of arms in some specimens, but usually wholly concealed. 

 Basal tentacle pores of arm minute and unprotected; second pah 1 

 with two or three short, thick, flattened arm spines (tentacle scales ?) 

 which carry little glassy points at tip; succeeding pores with three 

 or four (sometimes five) such spinelets, of which innermost is largest, 

 borne on a low, thick ridge just proximal to pore. Color (dried from 

 alcohol), cream-white to deep yellow. 



Localities. Albatross station 3317, Bering Sea, lat. 53 57' 40" N.; 

 long. 166 59' W., 165 fathoms, coarse sand, gravel, rocks, bottom 

 temperature 39.5, 1 specimen; station 3319, Bering Sea, lat. 53 40' 

 30" N.; long. 167 30' W, 59 fathoms, black sand, bottom tem- 

 perature 40.8, 8 specimens; station 3480, Bering Sea, lat. 52 6' N.; 

 long. 171 45' W., 283 fathoms, black sand, coral, rocky, 5 specimens; 

 station 4771, Bering Sea, lat. 54 30' N.; long. 179 17' E., 426 

 fathoms, broken shells, 4 specimens; station 4781, Bering Sea, lat. 



