15 LiGNiTic Stage 15 



This species was described from the Lower Cbiborne horizon 

 of Texas. It is found at Sniithville Bastrop Co. in moderate 

 numbers. 



The varietal name sylvtrntpis is proposed for a larger and in 

 some respecfts ver_v different form from Woods bluff, Ala. 

 Some of the differences have already been pointed out, and 

 others maj' be given as follows: costse in the typical form more 

 obtuse especially on the upper part of the spire; supercarinal 

 region more strongly marked in the smaller whorls and the sub- 

 sutural band prominent in all except the embryonic whorls. 



The varietal form is much larger, with a large body whorl 

 (our figure is of an exceptionally narrow or slender form) and 

 the supercarinal zone on the smaller spiral whorls is .smooth and 

 often without a subsutural band. 



Locality. — Ala.: Woods bluff. 



Type of variety a}id specimen figured. — Lea memorial collection, 

 Acad. Nat. Sci., Phila. 



Pleurotoma servatoidea, PI. 2, figs. 3, 4. 



Syn. P. servatoidea Aid., Bull. Am. Pal., vol. i, p. 59, pi. 5, fig. 5, 1895. 

 Aldrich' s original description . — Op. cit. 



I feel very confident that in the end this name will be with- 

 drawn in favor of PI. huppertzi Har. ; for the latter is subje(5l to 

 considerable variation as shown on pi. 4, Proc. Acad. Nat. Sci., 

 1895. This is the form referred to on page 58 of the Proceedings, 

 where huppertzi was described, in the following terms. "A very 

 closely allied form occurs at Woods bluff, Ala. The main differ- 

 ence consists in the different location of the retral sinus. In the 

 Alabama specimens it is located on the humeral angle while in 

 the Texan it is about one-third way from the angle to ths 

 suture. ' ' 



Aldrich's type from Gregg's landing is a little different from 

 the connuon Woods bluff specimens but is certainly identical 

 with the same. 



When well preserved, the young .show a slight carination as 

 indicated by fig. 4. Two or three rather conspicuous and distant 

 spiral lines are located on this carinal zone. 



