CRINOIDEA LARVIFOKMIA 



//.ifi/o'-riini*. Steining. (Fig. IM). I! five, // five, unequal. Three of the 

 radials composed of two pieces, of which 

 the uppenim-t oi- *njii-rr<nliii/ is the 

 larger, and bears an articular facet l<n - 

 the attachment of the arms. Anns 

 small, simple, uniserial, resting within 

 deep grooves formed along the side- ot 

 tlie orals. Orals large, pentagonal, and 

 laterally in contact ; the posterior one ^ 

 pierced by a small anal opening. Mouth 

 subtegminal ; column composed of thin 

 joints. Not uncommon in the Middle 

 Devoni-m of the Eifel and Nassau- ////'"/;,///.< /->/,;/;///!'.-, Goldf. Devonian; 



,> GerolstHn, Kif.-l. O, Calyx SP.MI from on,, Bide! 



<par<e in the Upper Devonian OI North b, Seen from above ; c, Seen from bdow ; A Dtaaram 



4 r . . of calyx ; h, Basals; ,/,tlm three tinsymmetrical plates 



America. situated between basals and radials; r, Radials; 



br, First arm-ossicle ; o, Orals. 



Family -2. Allagecrinidae. Etheridge and Carpenter. 



/; t'fi/i/.i- m-y *innlL Basak fire, md'uils Jit'e, of irregular form 



i and size. Some of the radials axillary and supporting two arms ; 

 a other* truncate and supporting but one arm ; their articular facets 

 l>r<>rided with, transverse ridges and large muscle plates. Upper 

 Sub-Carboniferous ; Europe and North America. 



.ll/it'tpcrinus, E. and C. B completely anchylosed in the 

 adult, and the suture lines between the orals also disappear- 

 ing with age. Stem largest next to the calyx, rapidly 

 tapering downward. Sub-Carboniferous ; Great Britain and 

 North America. 



Family 3. Pisocrinidae. Angelin. 



Cnft/.i- twwll, globose or cup-shaped, and composed of heavy 

 fi/ufcs. Busals three to five, radials five, very unequal, the right 

 posterior "in 1 rmnpound. Inferradial completely roofed over by 

 flif literal flanges of the wjicmidHtl and right antero -lateral 

 f>n/i"/. .-I mi* MIH/I/C, nniseridl, and composed of long, (///////////// ' 

 Silurian and Devonian. 





rixnc.fi HUS, de Kon. (Fig. 237, A). B five, unequal, 

 forming a triangle. Only the large anterior radial, and the 

 left posterior resting upon the basals ; the superradial of the 

 right posterior ray, and the right antero-lateral radial, being 

 ^M'P 01 ^'' 1 by the upper angle of the inferradial ; the latter 

 not in contact with the anal tube. Articular facets of the 

 '""-dials impressed between vertical partitions formed by the 

 hlteral margins of the plates. Tegmen rarely preserved; 

 but, as observed by Wachsmuth in P. pilula, consisting of 



/>1 T 11 !! 



nve large symmetrical orals, above which rises a long, 

 narrow, anal tube. Arms long, and composed of extremely 



elongate, heavy, cylindrical ossicles. Silurian ; Gottland, Dudley, England, and 



North America (Niagara Group). 





