MARYLAND GEOLOGICAL SUEVEY 171 



Marginella couuliis H. C. Lea, 1846, Trans. Amer. Philos. Soc, vol. ix, p. 273, pL 



xxxvii, lig. 102. 

 Porcellana conuluf> Conrad, 1863, Proc. Acad. Nat. Sci. Phila., voL xiv, p. 563. 

 Marginella {Volutella) conulus Meek, 1864, Miocene Check List, Smith. Misc. Coll. 



(183), p. 19. 

 Marginella minuta Dall, 1890, Trans. Wagner Free Jnst. Sci., vol. iii, pt. i, p. 57. 



Description. — "Testa ovata, glabra, alba; spira brevissima; anfract. 3; 

 columella subquadriplicata; apertiira aiigustissima. Long. 1, cliam. | 

 lin." Pfeiffer, 18 iO. 



" Shell siibovate, conoidal, thick, smooth, polished ; spire conical, ob- 

 tuse; sutures nearly obsolete; whorls three, flat; last whorl rounded; 

 base smooth; mouth long, very narrow; columella with three folds near 

 the base; outer lip thickened, rounded smooth." Lea, 1816. 



The Maryland specimens have been compared with Lea's type and 

 show no difference. Dr. Dall is authority for the equivalence of Lea's 

 species with Pfeiffer's. The latter was described from Cuba and is 

 recent, but also occurs in the Pliocene of North Carolina and Florida. 



Great care has to be taken in separating this species from the young 

 of Erato perexigua which occurs associated with it at Plum Point. 



Length, 3.5 mm.; width, 2 mm. 



Occurrence.— Ckottai^k Formation. Jones Wharf, Greensboro. 

 Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Cornell University, U. S. 

 National Museum. 



Marginella denticulata Conrad. 

 Plate XLIV, Fig. 5. 



Marginella denticulata Conrad, 1830, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st ser., 

 p. 235, pL ix, tig. 21. 



hurg, Virginia,^'' was read by Henry C. Lea before the American Philosophical Society 

 on May 29, 1843. An abstract of this paper is contained in the Proceedings of the 

 American Philosophical Society, vol. iii, p. 162, published in 1843, which con- 

 tains merely a list of species with descriptions of the new genera. In the library of 

 the Philadelphia Academy of Natural Sciences is a pamphlet entitled ^^Ahstract of a 

 Paper read before the American PJiilosophical Society, May 29, 1843, entitled '■Description 

 of some new Fossil Shells, from the Tertiary of Petersburg, Virginia,'' by Henry C. Lea, 

 Philadelphia,^^ which contains twelve pages octavo (numbered "1-12") of Latin 

 diagnoses of the new genera and species without figures, remarks or foot-notes. On 

 the first page is written ^'■Issued Oct. 19th, 1843." In 1845 there appeared a quarto 

 excerpt which was identical with the final publication in vol. ix, of the Transactions 

 of the American Philosophical Society, except that it had a pagination of its own. 

 Vol. ix in which the article made its final appearance was published in 1846. 



