CLASS III CEINOIDEA 225 



Subfamily B. Graphiocrininae Bather. 



No radianal. Anal x more or less between radials. Arms dichotomous, uniserial 

 to biserial. Infrabasals usually Jive, frequently minute, hidden by the column. Stem 

 usually round, cirriferous. Lower Carboniferous to Upper Carboniferous. 



Graphiocrinus K.on. (Scaphiocrinus I{a\l ; Phialocrinus TrsLutschold ; Aesiocrinus 

 Miller and Gurley) (Fig. 328). Calyx low, turbinate or obconic to bowl- 

 shaped. Infrabasals minute to fair size. Arms 

 uniserial, usually long, slender, branching once, 

 sometimes unbranched in one or more rays, making 

 the number variable from five to ten. Brachials 

 quadrangular. Ventral sac very large and con- 

 spicuous. Stem round, with long cirri throughout. 

 A genus of great stratigraphic range and wide . , . ,^'",.' . 



o o ° -*■ , ° __ ^ Analysis 01 Graphiocrinuf:. %h,In- 



distribution. Lower (Kinderhook) to Upper Car- frabasais;6, Basais ; r, Radiais ; 

 boniferous ; North America, Belgium and Russia. Bather). ' ' '^^'^"^'' '^^ 



Bursacrinus Meek and Worthen. Calyx obconic. 

 Arms rather broad, closely abutting, branching twice or more, to some extent 

 as in Zeacrinus ; uniserial, with quadrangular brachials. Ventral sac incon- 

 spicuous. Very rare. Lower Carboniferous (Burlington) ; Mississippian area, 

 North America. 



Delocrinus Miller and Gurley (Cerioerinu.s White, non Koenig). Similar to 

 Gra'phiocrinus, but with concave base, ventral sac inconspicuous, and heavy 

 biserial arms. Axillary primibrach frequently protuberant or spiniferous. 

 Lafrabasals at bottom of a deep funnel, hidden by column. Stem rather small, 

 round, cirriferous. Upper Carboniferous ; North America. 



Cibolocrinus Weller. Dorsal cup low, bowl-shaped. Lifrabasals three. 

 Other parts unknown. Permian ; Western Texas. 



Subfamily C. Encrininae Austin (emend). 



Dorsal cup ivith perfect pentamerous symmetry, having no radianal or anal 

 plate. Arms dichotomous, biserial ; usually heavy, and two to the ray. Ventral 

 sac inconspicuous or wanting. Lifrabasals Jive, coalesced into one, or atrophied. 

 Calyx usually low, bowl-shaped, with rounded or more or less concave base. Stem 

 usually round. Lower Carboniferous to Trias. 



Stemmatocrinus Trautschold. Base broadly rounded. Infrabasals coalesced 

 into a large flat pentagon. No anal x nor tube-plate visible in cup. Arms 

 ten, thick, closely abutting, and strongly resembling those of Encrinus 

 liliiformis. Lower Carboniferous ; Russia and North America. 



Erisocrinus White. Base rounded, with but little concavity. Infrabasals 

 five, fairly large, not in a funnel, usually visible outside of the stem. Anal 

 a; or a tube-plate rests on the upper surface of posterior radials. A close 

 derivative from Delocrinus, which it resembles in the arms and general form, 

 differing in the base and absence of anal plate in the cup. Upper Carbonifer- 

 ous ; North America. 



Encrinus C. F. Schulze (Chelocrinus, Calathocrinus v. Meyer ; Flabellocrinus 

 Klipstein ; (?) Cassianocrinus Laube ; (?) Traumatocrinus Wohrmann ; Porocrinus 



VOL. I Q 



