ASTKKOIDKA 01 NORTH PACIFIC ASH ADJACENT WATKUS FTSHKB -i 



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(i 1 . Adambulaeral spines provided with clusters of straight, or of straight 

 or except tonally willi only single p«-i ii<-«-lljiritte.* 

 6'. Adambulacrals diplacanthid, or mixed diplacanthid and triplacanthld, or hum-. I diplacanthid 

 and monaeant hid. 

 <•'. Dorsolateral plates noi arranged In fairly regular loi 



net, with or without the carinals in BO evident longJat • 



d'. Gonads opening dorsally; species never carry eggs and young Ceo far at 

 «'. A single series of actual plates either spl less superfleially bn 



or with a small single spine; a singli ir areas a 



with tin' aotinal plates; furrow spine ol alternate adambulaeral plates moi 



less advanced into furrow; infcromargiuul plates strictly aotinal in pot 

 supcromarginals defining ambitus; cross pediccllariae not unusually lark 



.1 i ,,h, ru Linnaeus Atleriat Linnaeus. 



actinaj plates in three to five prominent series [each plate hnaring o 



spines), separated by series of papular areas; furrow spine of alternate adam- 

 bulaeral plates often somewhat advanced into furrow; [nferomarginala usually 

 ■ aotinal but lateral in position; crossed pediccllariae not unusually 1 



Type, A. Irimchdii Stiiupson rrill. 



6*. No aotinal plates; with unusually large, slender-jawed, crossed pediccllariae; ahactinal 

 skeleton weak; marginal plates strong with one prominent superomargiici 

 still longer inferomarginal spine; adambulaeral plat' thid, with 



sometimes DUmerous straight pediccllariae along furrow margin; some of ' 

 occasionally attached to base of furrow spines but not usually. Typt 



canlhiiin linckii Muller and Troechel Uratlerias* Verrill. 



d>. Gonads opening vent rally; many species known to carry eggs and young; abactinal 

 skeleton more or less open, the dorsolateral plates usually irregular, but 

 sometimes in poorly defined longisei - usually small, normally with a 



small or fairly thick collar of pediccllariae: pediccllariae without en 



moderately broad terminal lip; one, or in large speoii 

 actinal plates; adarnbulacrals diplacanthid or mixed diplacanthid and monacanthid; 

 adambulaeral pediccllariae normally in clusters on the spines, but occurring singly 

 and even very sparingly in individuals which have few pediccllariae elaewbi 



body. Type, Asltracanthion muller i Sara - LeptaMerirut Verrill. 



<?. The dorsolateral plates have the appearance of being arranged in regular or -ubregular 

 longiaeriee; in either case the oarinals and marginals are always prominent and regular, 

 and the d d small papular areas form longiseries. 



of 1 . Ambulacra] pores not unusually large; gonads opening vcntralh ; adambulaeral- dipla- 

 oanthid <>r mixed diplacanthid and monacanthid Forma of L. camlti 



aequalis, and /.. hrxnetis ■ ..) /• part. 



(P. Ambulacral pores Unusually large (quadriserial); abactinal and marginal plat 



lobed, closely imbricated, with very small papular tteral plat 



three series pro\imally; ; rs of inimi' 



- of actinals pro\iuially; adambulaeral atly diplacanthid; gonad- unkl 



T> p< I, Type, I • rrill i \ ■ rrill. 



6 s . Adambulaeral plates monacanthid; with actinal plates in one Ini -.ing 



and [ g vcntralh paedophorii anbulacral 



spines rather few and inconspicuous, (Formal part. 



nan not sjiuvu hi 'ic marked with asterisk Fur i i Hamlsphan 



■ T' ;«"dlerllari«> (Ixilh crossed and straight, or either In . >tur» 



of AUrriat. a., fJKUteriai, Is pi vary In lb* 



■n of few iMsllocUitrtae, may almost or .julie lark pcdlcellarlae on the adai 

 they may have had). The character n fundamental and the few excel 



grofnlandica of the arctic Atlantic region usually lacks time pedlcelUi < have abundant adambulaeral 



ipine podlrellarta*. 



