62 PROCEEDINGS OF THE ACADEMY OF [1895. 



there seems to be no reason for doubting their identity. Meyer was 

 right in- referring this species to Pleurotoma, and PL nana would 

 stand were it not for the fact that Deshayes in 1824 (Desc. Coq. Foss. 

 des Env. de Paris, p. 482, vol. 2, pi. 68, figs. 19, 20, 21, 22) used the 

 same name for a Paris Basin shell. Cossman has referred Deshayes' 

 shell to the genus Homotoma (Bellardi, 1875) and has also referred 

 other specimens to this genus which in general resemble Lea's and 

 Heilprin's figures of nana Lea, and insignifica Heilp. At any rate 

 the generic affinities of nana Lea, and nana Deshayes are too close 

 to allow the retention of Lea's name; accordingly Heilprin's name, 

 insignifica, must be adopted. 



Lea's and Heilprin's characterization of this form being very im- 

 perfect, the following is offered: 



Size and general form as shown by the figure; whorls 8-10; 1, 2, 

 3 smooth, 4-8 with (a) a subsutural line, (b) a broad, faintly marked 

 concave zone, (c) a strong carinal stria and just above it sometimes a 

 faint line, (d) a strong subcarinal revolving line; body whorl with the 

 subsutural line or band ; the concave zone marked by curving longi- 

 tudinal striae and faint spirals; cariual angle 110; subcarinal space 

 with about twenty-five revolving lines somewhat alternating in size; 

 labrum within sometimes with one or two blunt, tooth-like elevations 

 located back some distance from the margin. 



Localities. Smithville, Bastrop Co. ; Little Brazos River, near 

 iron bridge, on Mosley's Ferry road. Also Claiborne, Ala. 



Geological horizon. Lower and Upper Claiborne Eocene. 



Type. Of nana at the Philadelphia Academy, of insignifica at 

 Mus. Nat. Hist. K Y. 



PI. (Mangilia) infans Mr. PL 5, fig. 10. 



iScobinella Iceviplicata Gabb, Jr. Ac. Nat. Sci. Phila., vol. 4, 1860, p. 380, pi. 



67, fig-. 20. 



Scobinella Iceviplicata Aid., MS., pi. 1, fig. 11. 

 Pleurotoma infans Meyer, Bull. Geol. Surv. Ala., No. 1, 1866, pi. 2, fig. 9. 



Meyer's specimens were evidently all young or imperfect, for in 

 the well-grown examples from Texas there are four adult whorls. 

 Moreover they show two large tooth-like projections on the inside of 

 the labrum, and not unfrequently two small plaits on the columella. 

 On the smooth sinus zone there is sometimes a fine spiral line, occa- 

 sionally there are two. 



Localities. Meyer gives for localities Red Bluff, Newton, and 

 Vicksburg, Miss. In the collection of the U. S. Nat. Mus. it occurs 



