292 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM. 



The fiU't tliut tliis variety is intermediate in many of its cliaracters between 

 leviuscula and aspera, that it is extremely variable, and is found frequently with 

 both aspera and leviuscula, or multispina, naturally suggests that it is a hj-brid 

 between the forms mentioned. There is much to support this idea, for the speci- 

 mens vacillate between the two species, never quite reaching either; nevertheless 

 there are examples which it is difficult to classifj^, as they might be considered either 

 as aberrant specimens of aspera (or sometimes leviuscula) or as extreme variants 

 of annectens. The "illogical" distribution of the variety makes one somewhat 

 suspicious also. 



The chief variation is in the size of the abactinal pseudopaxillse, as mentioned 

 above, these being narrow and with two rows of spinelets, or more oval ^vith three. 

 The marginal plates are usually abruptly narrower than the abactinal directly above 

 them, the latter being sometimes in irregular transverse lines (as in leviuscula) with 

 small secondary plates here and there between the lines. The marginal plates in 

 appearance are about halfway between the thin, sparsely armed aspera (with large 

 intermarginal papular areas) and the conspicuous many-spined plates of leviuscula. 

 A character of aspera is the incomplete actinal intermediate series, which does not 

 run the whole length of ray. The adambulacral plates are nearer lenuscula than 

 aspera, there being two transverse series of spines, wliile in aspera there is but one. 

 The double-furrow spinelet far along ray is about halfway between the two forms; 

 in aspera the double spinelet may occur on most of the plates of the distal two-thirds 

 of ray, or only on a few distal plates; in leinuscula it occurs only on a few distal 

 plates, or not at all. 



Madreporic body circular, sHghtly raised, similar to that of aspera, traversed 

 by a few radiating ridges bearing spinelets. 



Type.— C&t. No. 27781, U.S^.N.M. 



Type-locality. — Albatross station, 3095, off Oregon, 42 fathoms, rocks, stones, 

 shells. 



Distribution. — From Washington to Santa Barbara Channel, California, 21 to 

 73 fathoms. 



Specimens examined. — Fifty-seven, as follows: 



Specimens of Henrida leviuscula annectens examined. 



Locality. 



Depth. 



Nature of bottom. 



2874 Off Cape Flattery, Washington... 



2875 do 



2877 1 do 



2944 ' Near Santa Barbara Islands, California 



2951 ' do 



2964 1 Off Santa Barbara, California 



2965 do 



3095 OflOrtord Red, Oregon 



3120 ' Monterey Bay, Cahfomia 



3595 Admiralty Inlet, Washington 



3597 do 



4441 Monterey Bay 



4552 do 



35-28 

 7J-0G 



rocks and shells 



do 



black sand, mud 



rocky 



fine gray sand 



sand, stones 



do 



rocks, stones, shells . . . 



green mud, sand 



rocky, gravel, sand 



coarse black sand 



gray sand, black- timd. 

 green mud, rocks 



r. S. Xat. Mus. 



