42 BUI^LETIN 76, UNITED SIATES NATIONAL MUSEUM. 



<f= \ siiiRle well-developed eeriea of actinal intermediate plates between inferomarginals and 

 adarabulacral^ InferomarginaU broad, short, and band like, their spines many and 



appre<-<ed to ray. Ravs lone, disk small flenophoraster Fisher. 



r-. Madreporic body lai?;e, hidden by paxillse on its surface; anal aperature always present, large 



in Dipsacasler. . .. i r 



d' Margin of ray defined by inferomai^inals; superomarginals confined to abactinai surtace on 



ray; deep marginal fasciolar grooves; actinal intermediate areas large; no pedicellariae; 



paxilla; typical. 



f'. Gonads di.sposed in a series along either side of abactinai integument of ray, extending 



beyond middle; papula; distributed all over paxillar area Dipsacaster Alcock,,p. 85. 



e-. Gonads confined to interradial regions not extending into rays; papula absent from central 



portion of disk and a midradial band Patagiaster Fisher. 



d'. Margin of ray defined by both series of marginal plates which are small and armed with a 

 single small spine in addition to papilliform spinelets; marginal fa.scioles shallow; actinal 

 interradial areas small, and intermediate plates not extending far along ray; actinal granuli- 

 form pedicellariiB and low abactinai paxilte; closely related to Dytaster. 



LonchotcMter « Sladen. 

 Genus LEPTYCHASTER6 Smith. 



Leptychasler Smith, Ann. and Mag. Nat. Hist., ser. 4, vol. 17, 1870, p. 110. Type, L. hergue- 



lenensis Smith. 

 Leploptychaster Smith, Philos. Trans., Roy. Soc, Zool. Kerguelen Island, vol. 1G8, 1879, p. 278. 



(Emended from Leptychasler.) 

 Paraslropeclen Ludwig, Mem. Mus. Comp. Zool., vol. 32, 190.5, p. 7G. Type, P. inermis 



Ludwig. 

 Glyphaster Verrill, Amer. Nat., vol. 43, Sept., 1909, p. 5.53. Type, Leptychasler anomalus 



Fisher. 



Diagnosis. —Jiiiys normally five in number; abactinai surface flat or slightly 

 arched by inflation of dorsal integument; actinal surface beveled on sides; disk 

 variable in size, medium to small; rays typically of medium length, tapered; marginal 

 plates entirely without specialized spmes, the superomarginals typically very small, 

 the inferomarginals sliort and band-like; deep fasciolar grooves between specialized 

 transverse ridges of marginal plates, these grooves lined with close-set delicate 

 spinelets; abactinai area covered with true paxillse with subcircular to irregularly 

 stellate bases on papular areas; crown of paxilla with numerous very small spinelets; 

 papulae absent from a circular area in center of disk and from a conspicuous median 

 radial area (see Dipsacaster); actinal interradial areas small to medium sized, but 

 much larger than in Astropeden; actinal intermediate plates low-paxilliform, 

 imbricating; adambulacral armature, several longitudinal series of three to five 

 spinelets; mouth plates with long furrow margin, and inner spines enlarged; ambu- 

 lacral feet conical without a sucking disk; no pedicelleria?; superambulacral plates 

 present, though small; gonads interradial not extending along ray; anus absent or 

 sometimes present. 



KEY TO THE SPECIES OF LEPTTCHASTER HEREIN DESCRIBED. 



a'. Superomarginals small, forming a narrow margin tx) abactinai area; not conspicuously wider in inter- 

 radial angle than at middle of ray. 

 6'. Inferomarginals placed very obliquely, their specialized ridges when cleared of spinelets only 

 one-half width of intervening fascialar grooves at base of ray. Superomarginals paxilliform. 



arcticus, p. 43. 



<» Refers to L. tartareus in particular. 



ft All the evidence is against a typographical error, so the original spelling has been maintained in 

 accordance with modem usage. 



