ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATEBS FI8HEB. 259 



back in the Ecliiniisteridir, maintaiiiini; tlio suhfiimilics constituted l»y Viguicr, and 

 establishing a now subfamily, the Acantinistcrinir, for Acanthaster . 



In tliis report tlic genera Acanthaxter, M'Uhroil'm, and Valvastrr liave eacii been 

 made the typo of a tiistinct family. They have no more in common witli the 

 Echinasterina; of Sladen than havesome of the genera of the Solasteridn'; infact,are 

 more trenchantly separated, I think, than the latter. It is highly probable that the 

 three genera enumerated above are surviving types of once larger groups. 



The family Kchinasteri<l:e as limited in this report is therefore coextensive with 

 the EchinasteriniC of Sladen's Chalhnger Asteroidea, with the addition of genera 

 since described. The component genera are all included in the subjoined key. 

 They differ from AcanOtaster, Mitlirodia, and Valvaster in having (so far as known) 

 but one ampulla to each tube foot. The other differences are noted in the key to the 

 families of Spinulosa and accompanying footnotes. 



Ilenricia and Poraiiiopsis are the only genera which occur in the region covered 

 by this report. Clark has recorded Kchiixaster tenuispinus from Puget Sound," but 

 I do not believe his specimens came from that locality. The jiresence of such forms 

 in liis collection as .4r5oda steUata, Dia<kina mexicanum, Ecliinometra oblonga, Toxop- 

 neustes semituberculatus , and Clype.aster rotundus would at once arouse strong sus- 

 picions that two separate lots had in some way become mixed. Tliis is especiallv 

 the case since the labeling Avas evitlent ly i)oor. Echinaster or rather Othilia tenuispina 

 is from La Paz, Lower California. 



KEY TO THE KNOWN GENERA OF ECHINASTERm.E. 



«'. .\bactinal and lateral skeleton composed of lobed plate-s connected by intennediate ossicles 

 forming a more or less irregular mesh work. 

 6'. .\dambulacral spines or spinelols dispo.«ed in transverse series on each plate, or without 

 regularity; not arranged in a regular double longitudinal series. 

 c'. Abactinal plates bearing small epinelets, usually in groups, without a mamelon; usually 

 the skin hiding the plates is not thick and fleshy; the spineleta are never large and 

 isolated; frequently so email as to be granuliform. 

 d'. .\rtinal papula (i. e. between marginal and adambulacral plates); one or more spine- 

 lets on furrow face of adambulacral plates Ilenricia Gray, p. 266. 



cP. No papulsB between marginal and adambulacral plates (that is, none on actinal surface). 



«'. A sabre shaped spinelet on fiiirow face of adambulacrals Cribrastfr f> Perrier. 



e'. No spinelet in furrow rerknastfr 8laden. 



(?. Abactinal and marginal plates covered with a rather thick skin and bearing simple iso- 

 lated spines. 



a Proc. Bost. Soc. Nat. Ilist,, vol. 2!), 1901, p. 329. (See antea, p. 8.) 



6 I have never seen specimens of either Oibrastrr Perrier or I'crkruuUr Sladen and include ihom 

 here only on the authority of their de.-cribers. The generic diagnosis given by Perrier (Stcll<''ride!', 

 Cap Horn, 1891, p. 104) would apply to /^fjinViVi snni;i/mo/fn/a. In the description of C s/o'/rni how- 

 ever, it is stated that "face ventrale depourvue de papilles re.spiratoires." The genus is founded upon 

 a single specimen. 



Perknasler has been challenged by Ftell who calls it "only an aberrant Echiniuter." (The Echino- 

 derma found off the coa-st of South Africa. I'l. 2, .\stcroidoa, p. 253.) 



It is worth noting that the distinction used by Perrier in his key to the genera of Echina.'iteridiv 

 (1891 , p. 142), of disk small, Ilenricia, and disk rather large, CrihrasUr, I\rhna»ter, will not hold , as Ifrnrieia 

 san^inoleTila eschrichtii is sometimes nearly pentagonal. Neither does his statement that in Ilenricia 

 the ventro-lateral and marginal plates form series at the same time longitudinal and transverse, always 

 apply, for TJcnricia tanguinolenta constitutes an exception. In this species the character is variable. 



