MARYLAND GEOLOGICAL SURVEY 



453 



should be used for tlie third genus of the CViiiastolida. The author lias 

 not, however, been able to lind the definition of LiiJtasteriscns and prefers 

 to retain the name, for the present, in this new position. 



Genus LITHASTERISCUS Ehrenberg. 

 LiTiiASTERiscus RADLiTUS Ehrenberg. 



Plate CXXX, Fig. 9. 



LithmteriscHS r<((Ji>il>'s Ehrenberg, 1844, Monatsbericbte d. k. Akad. d. VViss. Berlin, 



p. 89. 

 LithasieriscHs radiatiix Ebrenberir, LS.i4, Mikrogeologie, \>\. xviii, tig. 113. 



Description. — " L. minor sul)glol)osus superfieie tulierculis elongatis 

 acutis aut subacutis unditpie radiata. Diam. — tV"-" Ehrenberg, 

 1844. 



This species is so simple in form that a very few words of description 

 suffice. The ten radial spines are apparently similar in form and size. 

 Thev are smooth and acutely conical. 



Occurrence. — Calvert Formation. Crisfield Artesian Well (T!)0 

 feet). 



Collection. — Johns Hopkins University. 



Suborder SPUMELLARIA. 



Superfamily DISCOIDEA. 



Family SPONGODISCIDA. 



Genus SPONGASTERISCUS Haeckel. 



Spongasteriscus marylandicus n. sp. 



Plate CXXX, Fig. 10. 



Description.— Arms at equal distances, of approximately the same size, 

 club-shaped, three times as long as broad at the outer end, four times 

 as long as broad at the inner end; two concentric rings in the central 

 disk; central disk surrounded by the suggestion of a patagium. 



Occurrence. — Calvert Formation. Lyons Creek. 



Co//ec^io/ts.— Maryland Geological Survey, Johns Hopkins University, 

 Eev. Edward Huber. 



