4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



mass of jumbled plates probably representing the under side of the 

 oral area or possibly an opening in the basal layer. The direction of 

 ambulacral curvature is uncertain, but two of the rays seem to curve 

 slightly to the right. 



The type and only known specimen collected by A. L. Carter, of 

 Kenmore, New York, and kindly loaned for description by the New 

 York State Museum, is so different from other edrioasteroids that 

 this new genus is here defined, although the surface characters cannot 

 actually be seen. 



Occurrence. — Chemung (Gowanda), Cattaraugus Creek, Versailles, 

 New York, ^ mile up creek from bridge. 



Holotypc. — Collection New York State Museum. 



Family HEMICYSTITIDAE. new family 



Theca composed of thin plates with an oral surface of five am- 

 bulacra separated by interambulacrals and attached by the greater 

 part of the aboral surface permanently or temporarily to some out- 

 side object. Oral covering plates three, one large plate next to the 

 anal area with two smaller adjacent ones. 



Hemicystites Hall, 1852, Cystaster Hall, 187 1, Cincinnatidisctts 

 Bassler, 1935, Carneyella Foerste, 1916, Streptaster Hall, 1872, 

 Lehetodiscus Bather, 1908, Foerstediscus Bassler, 1935, and probably 

 Pyrgocystis Bather, 191 5, all agree in the very definite number and 

 arrangement of the oral plates as well as the other characters men- 

 tioned above, so that this feature is believed to be of family importance. 



CYSTASTER Hall, 1871 



The view of the genotype C. {Hemicystites) gramdatiis (Hall) 

 on plate i, figure 14, clearly exhibits the generic characters, namely, 

 a theca in the form of an attached elevated elongate sack with five 

 short straight ambulacra, minute, fused, rounded or polygonal interam- 

 bulacral plates in mosaic, small scalelike marginal plates, and a raised 

 anal pyramid of very small nodose plates. 



CYSTASTER ULRICHI, n. sp. 



Plate 2, figs. 3-5 



This species, named in honor of Dr. E. O. Ulrich, is based upon a 

 single example about 4 mm in diameter attached to a ramose bryozoan. 

 It differs from the genotype and only other known species in the 

 shorter, broader sack forming the basal portion of the theca, and in 



