152 BUI.I,ETIN 31 153 



Grateloupia (Cytheriopsis) hydana Conrad, PI. 47. Figs. 12, 13 



C. hydatia Con., Foss. Sh. Tert. Form., Aug. 1833, p. 36. Harris' Re- 

 print, pi. 20, fig. 3. 

 Grateliipia mouHiisi'Le^a., Cont. to Geol., 1833, (Dec.) p. 59, pi. 2, fig. 



33- 

 Cytheriopsis hydana Con, Am. Jr. Conch., vol. i, 1865, pp. 7 and 146 ; 



vol. 3, 1867, p. 14. 

 Grateloupia moiilinsi de Greg., Mon. Faun. Eoc. Ala.,' 1890, p. 221, 



pi. 34, figs. 28-33. 

 Merctri.v dalli Cossm., Notes Compl., 1893, p. 11, pi. i, figs. 9, 10. 

 G. {Cyi.) hydana Dall, Trans. Wag., Ill, 1900, p. 1239. 



Conrad's original description. — Shell subtriangular, inequilateral ; 

 po.sterior side slightly channelled ; posterior end cuneiform ; lunule lance- 

 olate, elliptical. 



I gladly name this fine species in compliment to Mr. William Hyde, 

 one of the most successful and zealous cultivators of American Conchology. 

 Length 2 inches. Breadth i Yz inches. 



Locality. — Claiborne, Ala. Cab. Acad. N. S. 



I think Dall is correct in referring Cossmann's dalli to the 

 young of hydana, although it at first seems strange that in the 

 j'oung the posterior should be large and rounded, the anterior 

 acute, while in the adult the reverse is true. 



However, by examining small specimens and the umbonal 

 parts of larger ones, one is readily convinced that this change 

 takes place during the growth of the shell. Half -grown shells 

 when nearl}' equally pointed at either end de Gregorio calls var. 

 symeirica. 



Type.— Vhila. Acad. Coll. 



Horizon. — Claiborne stage. 



Specimens figured. — Paleont. Mus. Cornell Univ. 



Locality. — Claiborne, Ala. 



Gemma saneti-mauricensis, n. sp., PL 47, Figs. 14, 15 



Specific characterization. — Shell small, somewhat Astarte-\\\iQ. 

 exteriorl}^ as figured ; increments of growth well-defined, rounded, 

 becoming much less conspicuous on the anterior and posterior 

 margins which fall off rather abruptly ; lunule rather long, stri- 

 ate, and defined by a faint channel, not a sharpl}' incised line ; 



