MARYLAND GEOLOGICAL SURVEY 395 



arcuated series, which is recti linearly truncated above so as to leave in 

 that part a mere edentulous elevated line: wWiin destitute of striae: 

 margin with elevated angular lines : exterior surface with about thirty 

 longitudinal, impressed, acute lines, the intervals a little convex." Say, 

 183-i. 



The s])ecimens in the Philadelphia Academy of Natural Sciences 

 labelled '' Md." are similar in color to ones from the Yorkto-woi, Va., 

 region and have material between the teeth and in some holes in the shell 

 very suggestive of the same locality. I very much doubt their having 

 come from ]\Iaryland. 



Height, 33 mm. ; width, 3G mm. ; diameter, 11 mm. This is less than 

 usual size as found in Virginia and elsewhere. 



Occurrence. — Choptank Formation. Greensboro, Davis's Mill on 

 Choptank, near Skipton. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Superfamily NUCULACEA. 

 Family LEDID/E. 



Genus LEDA Schumacher. 



Leda liciata (Conrad). 



Plate CVII, Figs. 5, 6, 7, 8. 



Kucula liciata Conrad, 184:3, Proc. Acad. Nat. Sci. Pbila., vol. i, p. 305. 

 . Nucula liciata Conrad, 1845, Fossils of the Medial Tertiary, p. 64, pi. xx.wi, lig. 3. 

 Nucula liciata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 581. 

 Nnculaliciata Meek, 1864, Miocene Check List, Smith Misc. Coll. (183), p. 5. 

 Leda acrybia Dull, 1898, Trans. Waj^ner Free Inst. Sci., vol. iii, pt. iv, p. 590. 

 Leda phalacra Dall, 1898, Trans. Wagner Free Inst. Sci., vol. iii, pt. iv, p. .593. 



Description. — " Ovate-acute, ventricose, with about fifteen concentric 

 lamelliform striae; posterior side much shorter than the anterior; anterior 

 side slightly recurved, with an oblique slight submarginal furrow, causing 

 a slight emargination of the base near the extremity." Conrad, 1843. 



The above is Conrad's original description. His specimens are in the 

 Philadelphia Academy of Natural Sciences. A study of abundant mate- 

 rial shows that the concentric strige vary from fifteen, or fewer, to well- 

 nigh thirty, becoming at the same time finer and more indistinct over 



