138 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



of disk. The hepatic coeca are very long and voluminous, reaching nearly to tip of 

 ray. The gonads consist of a thick central axis and many lobulated divisions, short 

 on the side toward the body wall and long toward the mesial line. The opening is 

 close to the interbrachial angle and near the superomarginal plates, the series of which 

 bends upward to the dorsal surface at the base of the ray. The spacious ventral 

 stomach has very strong retractors. No Polian vesicles. 



Young. — Small specimens are generally easy to recognize on account of the dark- 

 tipped spines and unguiculate pedicellariae which may exceed the dorsal spines in length 

 by as much as 100 percent. (Station 3310, R 38 mm.) The smallest example from sta- 

 tion 2856 has R 33 mm., r 5 mm. The spines are relatively slenderer than in the adult 

 and though capitate are less conspicuously so than in larger specimens. The char- 

 acteristic fluting is already started but the grooves are fewer and occupy less of the 

 total length of the spine. The wreaths of crossed pedicellariae are well developed, and 

 while the unguiculate pedicellariae are as yet few they are very conspicuous by their 

 size. There is an irregular zig-zag series of three or four lobed dorsolateral plates, 

 with occasionally one out of place to spoil the regular order. Generally a secondary 

 ossicle intervenes between the spiniferous dorsolateral plates (but not between con- 

 secutive carinals nor marginals). The skeleton is very open and the actinal system 

 is present only in a few rudimentary plates at the base of the ray. In the mouth 

 angle the second pair of adambulacral plates barely touch. 



Type. — No. 1346, Museum of Comparative Zoology. 



Type-locality. — Alaska. Verrill 60 erroneously states that the type-locality is 

 Vancouver Island. The precise Alaskan locality is unknown, but the specimen was 

 taken by the Albatross. 



Distribution. — From Saghalien to Bering Strait thence to Gulf of Alaska off 

 Kadiak Island (Kamchatka, Commander Islands, Aleutian Islands, Bering Sea, 

 Alaska Peninsula). Bathymetrical range, low tide to 93 fathoms, on sand, gravel, 

 or sand and mud, or clayey sand. Known temperature range, 38.4° to 45.6° F. 



Specimens examined. — Fifty-four. 



Specimens of Lethasterias nanimensis chelifera examined 



"Shallow-water Starfishes, 1914, p. 186. 



