\-tkko||>k v 01 south PACIFIC tHD UXIACBNT WA.TMBB ii-mii: 89 



angle The dud pnonon between t J » * - dorsal lobes of two inferomargina] plates, nuns 

 distad and slightly downwards, t" open in the axillary < -hn n n«-I on a level with the 

 inferomarginal plates, or slightly below. There are two pulpy prominences ciu-e 

 to tin - innermost (reduced) inferomarginal spine and usually guarded by large straight 

 pedicellariae, which mark the opening They are situated on the actinaJ Burfaee, as 

 viewed from below, but olose to the margin. (PI. 26, o 



The interbrachial septum is tirm and thick (calcified) and extends about two- 

 thirds "f r toward the center of disk. 



/ .. , Cat. No. E 1492, U.S.N.M 



ZVps locality Ridge, Captains Bay, I'nalaska, lsso. \V. II Dall, Mo. I7#fl 

 1 1 specimen 



Distribution.- Prom Unalaaka to Semisopochnoi Island, Aleutian Islands. 



xamined. In addition to type, 17 from: Station 1777. Petrel Bank, 

 Bering Sea, northeast of Somisopochnoi Island, Aleutians, latitude 52 G 11' N , longi- 

 tude 179 49' E . 52 to 43 fathoms, lino gravel, three specimens. 



Station 4779, same locality, 54 to 56 fathoms, broken shells, pebbles, sand, 14 

 specimens. 



OAHTBI HATH » SECTION 



The Bpeciee of this section are, so far as known, restricted to the coasts liorderinp 

 the north Pacific and southern Berinp Sea. On the Asiatic side they have not been 

 • ided south of the Kuril Islands and on the American coast south of Santa Cata- 

 lans [aland, ( 'aid. 



All the forms are very variable. Species lines are extremely indistinct, some- 

 times hardly recognizable. For this reason descriptive term- have to be handled in 

 a relative manner, and figures are indispensable. Most of the species are ii comp 

 of small varieties or formae. Some of these form- perhaps represent incipient -p. 



Most of the Bpeciee have paucispinous and multispinous phases, as well as ooarse- 

 spined and slender-spined formae; ray- slender, medium, or robust. Various com- 

 binations of these extremes and their seemingly endless intermediate bout. 

 Even with a large series it is not possible to satisfy oneself of the systematic position 

 of every specimen. It i- not expected therefore that this treatise \mII sutli. 

 allocate every isolated specimen of which the name is required. Nor do I admit that 

 a few apparent exceptions will invalidate the whole systematic arrangement. The 

 careful investigator wfl] find many of his perplexities anticipated in the following 

 I have found tin- group more difficult even than the poiarit se< tion. 



The following is a list of the names which have been applied to or intended for 

 species of this group, in order of their prioritj 



I '. ehatica Brandt. Prodromus, 1836, page 270 Kamchatka This 



appears clearly t<> apply to the common 6-rayed Camchatkan Lepta I 

 tgriat eamtschatiea. 



■ ri.fi ktxaetia Stimpson, L862, page 272 Pugel Sound Types in the 

 United States National Museum; studied. Lspta I uaetia forma Aeseerit. 



Atte ri at aequalia Stimpson, 1862, page 278 Monterey. Calif. Type in Ui 

 National Museum; studied. LepUuttruu aeqiulit 



Atttriat taneouotri Perrier, 1876, page 64 Pugel Sound, Type in British 

 Museum; studied. L. htxaetit saaootawri. 



