202 BULLETIN 88^ UNITED STATES NATIONAL MUSEUM. 



Genus CHEIROPTERASTER Sturtz. 



Cheiropteraster Sturtz, PalseontograpMca, vol. 36, 1890, p. 228, pi. 29, fig. 33; 

 pi. 30, fig. 32; Verh. naturli. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 49, 68. 



This genus has its nearest relationship in Loriolaster, from which 

 it diffei"s in having a far larger oral opening and markedly different 

 ambulacral colunms. These are small plates, in shape hke the 

 vertebrae in teleost fishes, which alternate in adjoining columns and 

 do not closely adjoin medially. Podial openings unknown. 



Madreporite small, actinally situated near the mouth. 



Abactinal and interbrachial integument granular and thorny. 



Oral armature pieces small, described as ambulacral. 



Genoholotype and only species. — C. giganteus Sturtz (same citations 

 as above). This large species is very rare in the Lower Devonic 

 roofing slates of Bundenbach, Germany. 



Cat. No. 59381, U.S.N.M. 



SCHCENASTERID.E, new family. 



Specialized Cryptozonia with well-developed interbrachial arcs. 

 Abactinal area reticular, composed of numerous small plates. Inter- 

 brachial areas with distinctly imbricating plates. Oral armature 

 adambulacral. Adambulacrals well developed in the form of a rope 

 (hence the name, from schoinos, a rope). Ambulacral plates and 

 madreporite unknown. 



Contains : 



Scho&naster Meek and Worthen. 



Genus SCHCENASTER Meek and Worthen. 



Plates 32, 33, 35. 



Schoenaster Meek and Worthen, Proc. Acad. Nat. Sci. Philadelphia, vol. 12, 

 1860, p. 449; Geol. Surv. Illinois, vol. 2, 1866, p. 277.— Zittel, Handb. Pal., 

 vol. 1, 1879, p. 453. 

 Original description. — ''Animal consisting of a flattened pentagonal 

 disk, with the angles more or less produced in the form of rays or 

 arms, and the margins between the rays concave in outline, and 

 fringed with short, flattened, spine-hke appendages, which are also 

 continued part of the way out along the lateral margins of the rays. 

 Upper side of rays composed of a number of alternating sohd plates, 

 with the dorsal pores passing between them, while the angles between 

 the rays are filled with similar plates, forming the upper side of the 

 disk. Under side of the disk composed of numerous small plates, 

 very distinctly imbricating inward and laterally toward the ambu- 

 lacra. Ambulacral furrows (in the typical species) wide, deep, with 

 on each side a single row of comparatively stout, squarish, or oblong 

 adambulacral pieces, havuig an obliquely outward, imbricating 

 arrangement, so as to present somewhat the appearance of a twisted 



