198 ECHINODEEMATA PELMATOZOA SUB-KINGDOM in 



deep, generally with steep sides. Deltoids small, confined to the truncated 

 upper face of the calyx. Lancet-plates in all but one species (P. caryophyl- 

 latum) concealed by the side-plates ; outer side-plates very small. Spiracles 

 rarely present. Hydrospires pendent, and opening externally by a series of 

 elongate slits with intervening ridges, distributed in sub-parallel order on the 

 sloping sides of all the radial sinuses. The slits are only partially covered 

 by the ambulacral plates, and are sometimes visible for their entire length. 

 Lower Devonian ; Spain. Sub-Carboniferous ; Europe and North America. 



Cryptoschisma, E. and C. Calyx elongated, with a broad, flat, truncated 

 upper face. Radial sinuses wide and open, their sloping sides pierced by 

 hydrospire-slits, which are completely concealed by broad, petaloid ambulacra. 

 Spiracles small, single, or more rarely double ; in the latter case the posterior 

 pair are confluent with the anus. Represented by the solitary species C. 

 Schultzi, d'Archiac et de Vern. Lower Devonian ; Spain. 



Orophocrinus, v. Seebach (Codonites, M. and W.) Calyx balloon-shaped to. 

 truncate ob-pyramidal, with more or less concave upper face. Section dis- 

 tinctly pentagonal or stellate. Ambulacra narrow, linear to sub-petaloid. 

 Deltoids generally visible in side-view, the posterior one wider than the 

 others. Spiracles ten, varying from wide clefts along the sides of the ambu- 

 lacra to narrow slits at their upper ends ; the posterior pair separate from 

 the anus. Hydrospire-slits almost completely concealed, being concentrated 

 at the bottom of the radial sinuses. Stem round, composed of short, nearly 

 equal joints. Pinnules extending to nearly twice the height of the calyx, of 

 uniform thickness throughout, and composed of sharply cuneate pieces inter- 

 locking from opposite sides ; ventral furrow wide, and covered by small pieces. 

 Sub-Carboniferous ; Great Britain, Belgium, and North America. 



Order 2. IRREGULARES. Btheridge and Carpenter. 



Non-pedunculate Blastoids in which one ambulacrum and the 

 corresponding radial are different in form and size from the 

 others. 



Family 1. Astro or inidae. T. and T. Austin. 



This family embraces the three rare genera Eleuthero- 

 crinus, Shum. and Yandell (Fig. 325), occurring in the 

 (iumani Devonian of North America ; Astrocrinus, Austin ; and 

 Lower Devonian ; Ky! Pentephyllum, Haughton. The two latter forms are found 

 ancuT)' 2/1 ' in the Carboniferous Limestone of England and Scotland. 1 



1 [The substance of the editorial notes in brackets occurring throughout the Crinoid and Blastoid 

 chapters has all been very kindly communicated by Mr. Charles Wachsmuth. Much of this matter 

 embodies the results of original and as yet unpublished observations. Special acknowledgments are 

 therefore due to Mr. Wachsmuth, without whose generous assistance the above-named chapters of 

 the present edition would have been imperfect in many respects. TRANS.] 



