which is absent from the fossil form. C. mactracea has not been seen by me 

 in the fossil state if this character be required. However, I find southern 

 specimens of the recent shell otherwise apparently identical are without the 

 radial striation. The young shells are more transverse and more flattened as 

 a rule; in outline and color they vary within wide limits. I find in one lot 

 from a single locality specimens which might represent C. guadalupensis and 

 C. martinicensis of Orbigny, C. fastigiata Gould, and C. parva C. B. Adams. 

 I confess myself unable to formulate a diagnosis which will characterize more 

 than one species among the recent forms of the Atlantic coast, though it is 

 undeniable that specimens may be selected which will seem, without the con- 

 necting series, perfectly distinct. The fossil forms appear much more uniform 

 in their characters. As lunulata is unquestionably the oldest specific name there 

 is no doubt as to what we shall call the fossil, but the decision as to the recent 

 forms must await better information. 



Orassatellites ( Crassinella ) galvestonensis Harris. 



PLATE 49, FIGURE 14. 

 Eriphyla galvestonensis Harris, Bull. Am. Pal., i., No. 3, p. 8, pi. i., figs. 2a, 2b, 1895. 



Miocene of artesian well at Sea Isle City, New Jersey, at a depth of seven 

 hundred and eighty-five feet, young specimens (Woolman) ; of St. Mary's, 

 Maryland; Yorktown, Virginia (figured), and adjacent localities on the York 

 River, and of the Galveston, Texas, artesian well, at a depth of four hundred 

 and forty to four hundred and fifty-eight feet (Gwyn), the typical locality. 



This form is rather convex, nearly equilateral, with very arcuate and some- 

 what swollen base, and is more nearly destitute of sculpture than any of the 

 other species. The adults reach a height of 5.2 mm., a width of 5.5, and a 

 diameter of 3.0 mm. A large proportion of the specimens found have been 

 quite young and small. 



Crassatellites (Crassinella) duplinianus n. sp. 



PLATE 50, FIGURES 5, 6. 



Miocene of the Natural Well and Magnolia, Duplin County, North Caro- 

 lina, and Pliocene of Tilly's Lake, Waccamaw River, South Carolina; Burns 

 and C. W. Johnson. 



Shell small, subtriangular, solid, with markedly acute beaks, which incline 

 backward; anterior slope convexly arcuate, long; posterior slope nearly a 

 straight or slightly concave line, shorter ; lunule and escutcheon extending the 

 whole length of their respective slopes, long and narrow, the latter more ex- 



