1896.] NATURAL SCIENCES OF PHILADELPHIA. 471 



Instead of making this a new species, we might speak of it as a 

 marked variety of aldricJii, which itself is a variety of perovata Con. 

 It seems to us, however, better to designate it by a new name. A 

 variety of this species shows concentric liroe over its entire outer 

 surface. 



Locality, Jackson, Miss. 



Tellina eburneopsis Con. PI. XVIII, fig. 6. 



Locality, Jackson, Miss. 

 Mactra mississippiensis Con. var. PI. XVIII, fig. 7. 



Locality, Jackson, Miss. ' 

 Periploma sp. PI. XVIII, fig. 8, 8a, 8b. 



Owing to the descriptions by Lea and Meyer of two fragmentary 

 specimens of Periploma, it is now unsafe to propose a new name for 

 this specimen. It differs considerably from either Lea's or Meyer's 

 figures and diagnoses, but Meyer has stated (Ber. iiber die Senck. 

 Nat. Ges. in Frank. A. M., 1887, p. 16) that his P. compHcata occurs 

 at Jackson, 



Locality, Jackson, Miss. 



Eucheilodon creno-carinata Heilp. PI. XVIII, fig. 9. Proc. U. S. Nat. Mus., Vol. 

 3, 1880, p. 150. 



Several specimens of this species, of a moderate size and rather 

 imperfect, are among the Jackson material of this collection. A 

 specimen, perhaps the adult of this species, is shown by fig. 9, pi. 

 XVIII. The humeral carina, instead of being simply finely crenu- 

 late, is regularly nodular ; moreover, there are thin, strong, revolv- 

 ing ribs on the part of the whorl below the carina. It is quite 

 possible this should be regarded as a distinct species, yet it is unsafe 

 to propose a new name until more material is at hand. 



Locality, Jackson, Miss. 

 Pleurotoma (Ancistrosyrinx) columbaria Aid. 



Aldrich described this species (Geol. Surv. Ala., Bull. 1, 1886, 

 p. 31, pi. 6, fig. 9) from a fragment. The Lea Memorial Collection 

 possesses a least one perfect specimen. Hence, in continuation of 

 Aldrich's description it may be said : aperture slightly exceeding 

 the spire in length ; from the dentate carina downward on the body 

 whorl to the end of the canal, there are many granular spiral lines; 

 from the dentate carina toward the suture above, two coarse granu- 

 lar spiral lines are found ; inside of these spirals the humeral zone 

 is smooth, save faint traces of deeply curved longitudinal lines, the 

 retral curvature is confined to this smooth zone. 



