422 PROCEEDINGS OF THE ACADEMY OF [PaRT II 



Length 33, alt. 31, diam. of one valve 13 mm. 



Type no. 2768 A. N. S. P. 



This species has been placed in the synonymy of C. serratum, but 

 it seems to me distinct by the far larger beaks, of a different shape, 

 and the differences in the teeth. In C. serratum the beaks are much 

 wider and lower, even in specimens of far greater size. The sculp- 

 ture described may possibly be due to disintegration of the outer 

 layer, though we see no evidence that this is the case. 



VENERIDAE. 



Macrocallista (Chionella) maculata (L.) 



M. (C.) maculata L., Dall, Trans. Wagn. Inst., iii, p. 1256. 

 Agrees closely with recent specimens externally. As the valves 

 are together the interior could not be compared. 



Macrocallista (Chionella) planivieta (Guppy) 



Cyiherea {Callisla) planivieta Guppy, Q. J. Geol. Soc.,xxii, 1866, p. 292, pi. 



18, fig. 3. 

 Callista planivieta Guppy, Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 250. 



One typical right valve (no. 2670). 



Pitar tryonianus (Gabb) Plate XLVIl, flg. 11. 



Callista tryoniana Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 250. 



This shell is not unlike the recent P. fulminata Mke. (varians 

 Hanley), but is thinner, a little plumper, with the beaks turned for- 

 ward a little more. The sculpture is of very fine, close, even and 

 smooth concentric threads, which are flattened and wider in the 

 median part, where unworn; the beaks smooth in the median con- 

 vexity. The lunule is defined by a weakly impressed line. 



Length 28, alt. 23.3, semidiameter 8.4 mm. 



Type no. 2757 A. N. S. P.; a left valve. 



Cf. Pitaria cercadica Maury, which appears to be the same species. 



The emendation of Pitar into Pitaria was an arbitrary proceed- 

 ing. There are many non-Latin generic and specific names which 

 might equally well be changed to give them a Latin dress. 



Pitar (Hyphantosoma) carbaseus (Guppy) 



Cytherea (Circe) carbasca Guppy, Q. J. Geol. Soc, xxii, 1866, p. 292, pi. 18, 



fig. 13. 

 Callisla carbasea Guppy, Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 250. 

 Pitaria (Hyphantosoma ) carbasea Guppy, Dall, Trans. Wagn. Inst., iii, p. 

 1266. 



Six specimens contained in trays no. 2664 and 2679. 



Pitar (Lamelliconcha) acuticostatus (Gabb) Plate XLVII, flg. 10. 



Callista acuticostata Gabb, Tr. Amer. Philos. Soc xv, 1873, p. 250. 

 The sculpture consists of close, nearly equal, thin concentric ribs 



