DESCRIPTIONS OF THB SPECIES. 147 



(ii.) Subfamily ScHizoBLASTiD.fi, I'. & C, Ism;. 



Nii anal plate. Posterior spiracles may be fused with anus. 



Schizoblastus, E. & C. Oryptdblastua, E. & C 



Acentrotremitcs, E. & ( '. 



4th Family. GBANATOBLAJSTIDJE, E. & C, 1886. 

 Calyx globular or ovoidal, with flattened or concave base and linear ambulacra. 

 Spiracles five, piercing the deltoids ; or ten, grooving their lateral edges. 



Granatocrinus, Troost. Heteroblastus, E. & C, 1886. 



5th Family. CODASTEBID^E, E. & C, 1886. 

 Base usually well developed and sometimes very long. Some, or all of the 

 hydrospire-slits pierce the calyx-plates ou the sides of the radial sinus, restricted 

 portions of which may remain open as the spiracles. 



(i.) Subfamily P1LEX0SCIIISMID..E, E. & 6'., 1886. 

 Eight or ten groups of hydrospire-slits, which are partially or entirely visible. 

 Deltoids limited to the summit, not appearing externally. 



Codaster, McCoy. Ehanosc/tisma, E. & C. 



(ii.) Subfamily CinTTOS(/HisMiD.E, E. & C, 1886. 

 Ten groups of hydrospire-slits, few or none of which appear at the sides of the 

 ambulacra. Deltoids small and external, or limited to the summit. 



OrophocrinHs, von Seebach. Cryptomhisma, E. & C. 



Order I R 11 E G U L A R, E S, E. & G., 1 886. 



Unstalked Blastoids, in which one ambulacrum and the corresponding radial are 

 different from their fellows. Base usually unsym metrical. 



6th Family. ASTBOCfilXID.E, T. i: T. Austin, 1842 (emend. E. & C, 1S86). 

 (i) Basals unsymmetrical. Azygos radial small and without definite limbs; its 

 ambulacrum short, wide, and horizontal. 



Astrocrinus, T. & T. Austin. Eleutherocrinus, Shumard & Yandell. 



(ii) Basals symmetrical ; odd ambulacrum linear. 

 Pentephyllum, Haughton. 



u2 



