2 78 BULLETIN 82, U^ITEO STATES NATIONAL, MUSEUM. 



Comngter minimiix. Amphimetra spectabilis. 



Comaster multil>rac]iiata. Stephannmetra echinus. 



Comaster fruticosvs. Stephanometra monacanthd. 



CotnaMcr distincta. Oxymetra flnschii. 



Comaster parvus. Oxymetra aranea. 



Comaster taviana. Dichrometra ciliatn. 



Comaster delicata. Dichrometra fiageUata. 



Comantheria polycneniis. Mariametra subcarinata. 



Comantheria brinreus. Lam.prometra palmnta. 



Comanthina schlegelii. Lam,promf.tra protectus. 



Comanthus pinguis. Cenometra unicornis. 



Comanthus solaster. Cenometra delicata. 



Comanthus japonicus. Cenometra herdmani. 



Comanthus trichoptera. CyUometra disciformis. 



Comanthus beiihami. CyUometra albopurpurea. 



Comanthus waMbergii. Oligometra sen-ipinna. 



Comanthus samoana. .intedon petasus. 



Comanthus annujata. Antedon bifida. 



Comanthus parvicirra. .intedon adriatiea. 



Zygometra mirrodiscus. Promaehocrinus kerguelen-iis. 



Zygomctra eJegans. Fariometra explicata. 



Catoptometro magnifica. Triehometra vexator. 



Himernmetra magnipinna. Thaumatometra nutrix. 



Himerometra robustipinna. Thaumatocrinus rvgosus. 



o". Definite plates present in Hie nmbiilacral lappets or in the lateral perisome of the pinnules 

 between them and the pinnulars, or in both situations. 

 6'. Two series of plates or spicules present : a plate or spicule in each ambulacral lappet and 

 another between this and the border of the pinnulars. 

 &. Plates of both series large, conspicuous and highly developed, the lateral perisome of 

 the pinnules and the ambulacral lappets being completely inclosed by them ; 

 plates in the lappets more or less circulnr, oval, or reniform; lateral plates with a 

 narrowly produced distal and broad proximal process, and on the inner side two 

 prominent ridges, the distal curved and usually interrupted, the proximal straisht, 

 at right angles to the pinnulars, and carrying the covering plate articulated to 

 the outer end. 

 (i'. No supplemental y side plntes present. 



e\ The saeculi do not pierce or notch the side plates. 

 Ptilometra macronema. Pterometra magtHpeda. 

 Ptilomctra miilleri. Pterometra splcndida. 



Asterometra anthus. Pterometra pulcherrima. 



Asterometra macropodn. Pterometra triehopoda. 

 Asterometra rristata. 

 e'. The saeculi reach the exterior through holes in the side plates, or through 

 gaps between them formed by two apposed notches. 

 f. The outer portions of the saeculi pass to the exterior through apertures 

 formed by two rounded notches in the adjoining ends of ad.1acent 

 plates. 

 Ncometra alecto. Calometra discoidea. 



Neometra acanthaster. GepJiyrometra propinqua. 



Weometra conaminis. Pectinometra cnrduum. 



Jfeometra gorgonia. Pectinometra fiavopurpurca. 



Calometra calHsta. Ptilometra macronema. 



