432 TRANSACTIONS OF THE WAGNER FREE 



In the Proceedings of the Academy of Natural Sciences for 1884 (p. i lo), 

 Dr. O. Meyer has described a minute fossil — which he regards as a Pteropod, 

 perhaps a subgenus of Cuvierina — under the name of Tibiella Marshii n. g. et 

 sp. It was obtained from the Claiborne sands, but, as I have not had an op- 

 portunity of examining the type, I prefer to leave its relations undiscussed. 



Genus CRESBIS Rang. 

 This genus is distinguished from Styliola, which has a dorsal groove and 

 twisted shell, by its simple, slender, conical shell, hardly distinguishable from 

 some forms of Dentalium, except by the fact that it is usually not quite recti- 

 linear or curved in a perfectly even manner, and, when perfect, is closed at the 

 smaller end. 



Creseis recta Lesueur. 



Styliola recta (Lesueur MS), Blainv., Man. Mai. ii. p. 655, 1827; Lesueur, Walnut Hills 



Foss. Sh., pi. I, fig. 12, 1829 ; Verrill, Trans. Conn. Acad. v. p. 556, 1882. 

 Creseis aciciUa Rang, Ann. Sci. Nat., 1. xiii. p. 318, pi. 17, fig. 6, 1828. 

 C. clava and C. acus Rang. 

 Creseis recta Dall, Bull. U. S. Nat. Mus. No. 37, p. 80, No. 13, pi. 66, fig. 118, 1889. 



Chesapeake Miocene of the"Tellina bed," Temple Place, York River, 

 Virginia, Harris ; living, between N. lat. 48° to S. lat. 40°, pelagic in the 

 Atlantic Ocean. 



The specimens cannot be discriminated from the recent form, which is, 

 moreover, quite variable within the narrow limits prescribed by its simple 

 character. 



Lesueur figured this by the side of his Vicksbiirg fossil {C. hastatd) to 

 show the difference. He referred both to his genus Styliola, but a year or two 

 later Rang proposed his genus Creseis, founded on this very species, and, the 

 type of Styliola being a grooved species {S. siibulata Q. and G.), when the dis- 

 tmction was recognized, both names were retained. 



Subclass ISOPLEURA. 



Order POLYPLACOPHORA. 



Superfamily EOCHITONIA. 



The antiquity of the Chiton stock is extremely great. In America they 

 are recorded {Priscochiton canadensis Billings) from the Lower Silurian. The 

 subject has been reviewed, so far as the groups earlier than the Tertiary are 

 concerned, by the writer in the Proceedings of the U. S. National Museum for 

 1 88 1, pp. 279-291. On the Pacific coast, where Chitonidce abound in the 

 recent fauna, the Pleistocene contains numerous fossil remains of still existing; 

 species. Putting all the foregoing aside, in the Tertiary of the Eastern States 

 but very few species are known. 



