13 LiGNiTic Stage 13 



degree and not of total absence of features in one and not in the 

 other. De Gregorio speaks ( Mon. Faun. Eoc. Ala., p. 25) of 

 the apparent identity of childrcni and denticida. Cossmanu 

 admits that the two belong to the same sedlion but notes the 

 more distant crenulations of the latter. This distinction does not 

 however hold when the Lignitic Eocene specimens are taken into 

 consideration. Dixon's figure of //d'i^'^za is a splendid representa- 

 tion of some of our lyignitic forms. Heilprin remarks that 

 Gabb's nodocarinata from Texas belongs to this species. This 

 however is a mistake and has alread)^ been accounted for (Proc. 

 Ac. Nat. Sci. Phila., 1895, p. 59,. 



Strangely enough neither Meyer nor Heilprin mention the 

 identity oi cliildreni and denticida, but Meyer regards the latter 

 as equivalent to P. baumonti Lea. P. baiunonti is probably but a 

 well marked variety of denticida or cliildreni, but wnth its one 

 spiral passing through obique nodules it varies considerably from 

 denticida. A variety of the same has recently been figured by 

 Vaughan as P. learchi (Bull. Geol. Surv. No. 142, pi. 2, fig. i, 

 1896). Gregorio's comparing childreni with nupera Con. and 

 tercbratis Lam. is inexcusable. 



Other forms will be noted in our monographs on the Lower 

 Claiborne and Claiborne stages. When all available American 

 material has been worked over several varietal names can 

 well be given to this variable species. 



Lignitic localities. — Ala.: Woods bluff, Gregg's landing. 



specimen Jigured.—'PX. i,fig. 21, Woods bluff ; fig. 22. Gregg's 

 landing: Paleontological Museum, Cornell Univ. 



Pleurotomanebu!osa, n. sp., PI. 2, fig. i. 



Specific characterization. — Size and general form as indicated 

 by the figure; whorls 9; i, 2, and 3, smooth, small; 4, 4)^ faintly 

 plicate longitudinally above but more strongly so below; remain- 

 ing whorls ornamented by ribs strongest in a medial portion of 

 the whorl, .slightly obliquely set, extending faintly to the left 

 and above to the sub-sutural band where a nodular enlargement 

 takes place; above, the ribs extend nearly from .suture to .suture, 

 below, they are more limited and sometimes nearly vanish on the 



