1888.] NATURAL SCIENCES OF PHILADELPHIA. 171 



In two cases only did he try to give synonyms and definite 

 names. The species of Ccecum of which he found nearly a dozen 

 specimens, agrees with a specimen of Cceewn anmdatum Emmons, 

 in the collection of the Academy, which species has been described 

 from the Tertiary of North Carolina. He was unable to distinguish 

 the form specifically from specimens of Ccecum jndchelium Stimpson, 

 from the Atlantic coast of America, and considers specimens of 

 Ccccuvi trachea Mont., from the Atlantic coast of Europe as belong- 

 ing to the same species. 



Cerithiopsis davnlus H. C. Lea, sp., of which species he found a 

 specimen with smooth embryonic whorls in material from York- 

 town, Va., agrees with the recent Cerithiopsis terebralis Adams, 

 from the Atlantic coast, Florida specimens of which show three 

 and a half smooth embryonic whorls. If the nucleus of Ceonthiopsis 

 ierehralis should agree with the nucleus of the European Cerithioj)- 

 sis trilineata Phil , the two species would be identical and the name 

 ■of Phili])pi would have the priority. 



Aligena sharpi, n. sp. Convex, subrotund, somewhat oblong, 

 posterior margin slightly truncated. Beak small. Hinge with one 

 small cardinal tooth. Ligament internal in a shallow sulcation, 

 running from the beak past the dorsal margin obliquely posteriorly 



and interiorly. Anterior muscular impression 

 much elongated ; posterior muscular impression 

 oval. Pailial line apparently entire. Surface 

 with irregular prominent strise of growth. 

 Only the figured specimen was found. 

 The genus A ligena is not mentioned in the 

 Manuals of Conchology of Tryon and of Fisch- 

 er. It was founded by H. C. Lea (Trans. 

 . — . Amer. Philos. Soc. (2)' vol. IX, p. 238.) in 



1843, and was defined by him in the following way: — "Shell equi- 

 valve? subequilateral, closed posteriorly and anteriorly; hinge with 

 one cardinal tooth and a long shallow sulcation under the beaks. 

 The cardinal tooth is in general rather small. The sulcus appears 

 to have received the ligament. It commences at the beak and runs 

 ■obliquely past the dorsal mai-gin into the cavity under the beak." 



The two species of H. C. Lea have been placed by the authors 

 after him, in the genus Kellia. In accordance with it Dr. Meyer 

 has (at another place) enumerated Kellia laevis H. C. Lea, among 

 the fossils which occur at Yorktowu Va. But an examination of 

 recent species of Kellia, especially of Kellia siihorhicularis Mont., 

 made him believe that these Miocene shells should not be placed in 

 this genus. 



The two species Aligena leavis H. C. Lea, and Aligena striata 

 H, C. Lea, do not differ in shape from each other and are probably 

 identical. A. Sharpi, however, differs from them greatly in shape, 

 being more rounded and more inflated. 



