ORDER ii CRINOIDEA CAMERATA 137 



Cupressocrinus, Goldf. (Fig. 238). Tegmen very small; the greater part of 

 the ventral surface covered by the so-called consolidating apparatus. This is 

 composed of five petaloid, horizontally truncated interradial pieces, which are 

 laterally in contact, and enclose a large, central open space. The opening was 

 probably covered by orals, as in Symbathocrinus ; while the consolidating plates 

 served for the attachment of muscles. Five round apertures, through which the 

 ambulacra entered the calyx, perforate the divisions between the consolidating 

 plates ; one of the latter is pierced by the anal opening (Fig. 238, ). Arms 

 provided with a wide and deep ventral furrow, lined on both sides with jointed, 

 closely abutting appendages ; of these there are several to each arm-plate, thus 

 showing that they are different from true pinnules. Middle Devonian ; Eifel, 

 Harz, Nassau, and Westphalia. C. crassus, elongatus, abbreviatus, Goldf. 



Mf/rtillocnnus, Sandb. Calyx deep ; tegmen formed by five large symmetri- 

 cal orals resting directly upon the radials. IB fused into a single plate, and 

 pierced by the quadripartite canal of the stem. Devonian. 



Family 6. Stephanocrinidae. Wachsmuth and Springer. 



Calyx cup-shaped, composed of three elongate basals, five radials, and five inter- 

 radials. Radials deeply forked ; the prongs formed by the margins of two contiguous 

 radials extending upward between the arms, and building together with the interradials 

 a row of pyramids. Radial incisions occupied by the ambulacral grooves, which are 

 roofed over by two rows of covering pieces ; those of 

 the same row closely anchylosed. First costals semi- 

 lunate, and resting within a horseshoe-like concavity 

 near the outer end of radial incisions. Tegmen 

 constituted of five large triangular orals. Arms 

 very short, composed of about ten pieces, all of which 

 are axillary, and give off side arms. The latter are 

 biserial, non-pinnulate, and are made up of long, 

 strongly cuneiform joints. Ordovician and Silurian. no 239 



Stephanocrinus, Conrad (Rhombifera, Barr.), stephnnocrinus anguiat-us, Conrad, sii- 

 (Fig. 239). This unique genus is distinguished O f S^nKi ST^BunTmif 

 from all other Larvifwmia by the biserial and ^SLk^a^aftSnaU)?" f the 

 branching character of the arms, as well as by 



the presence of small interradials. Anal aperture situated near the summit of 

 one of the interradial projections. Ordovician (Etage D) ; Bohemia. Silurian ; 

 North America. 



Order 2. CAMERATA. Wachsmuth and Springer. 



(Sphaeroidocrinacea, Neumayr. ) 



The lower arm-plates incorporated into the dorsal cup by means of supplementary 

 plates. All plates of the calyx united by close sutures, and immovable. Tegmen in 

 the form of a solid vault, composed of rigidly united plates. Mouth- and food-grooves 

 completely covered; the covering pieces of the latter frequently incorpoi'ated in the 

 tegmen. Anal opening eccentric or subcentral, frequently situated at the end of a 

 proboscis-like anal tube. Interradials constantly present in all interrays ; inter- 



