10 University of Texas Bulletin 



ornamentation there are striations or lines of growth be- 

 tween the ribs. Sometimes there is a wider space between 

 the two middle ribs than there is between the others. 



This species is distinguished from Turritella vibrayeana, 

 D'Orb. by the size of the apical angle which is 12 in the 

 latter species, by having plain intermediate lines or ribs 

 instead of nodular ones as occur in T. vibrayeana. 



Our species resembles Turritella budaensis f but in the 

 latter species the apical angle measures 21, the sutural 

 angle 6, the whorls are convex, the two middle ribs are 

 much larger and more prominent than the other two ribs, 

 and between the two middle ribs are two lines instead of 

 one. These characteristics readily distinguish T. budaensis 

 from our species. T. bartonensis is distinguished from 

 T. planilateris in the size of the, apical angle. Turritella 

 planilateris has only one intermediate small rib and the 

 spaces between the ribs are much narrower than in this 

 species. 



Number of specimens. 35 and some fragments. 



Occurrence. Upper Buda limestone, Shoal Creek and 

 Barton Creek. 



Austin, Texas. 



Turritella budaensis Shattuck 

 Plate II, figures 4, 5, 6 



Turritella budaensis Shattuck, 1903 



Bulletin of the United States Geological Survey, 



No. 205, 1903, PL XIX, Figs. 4-6 



Dimensions. Apical angle 21, sutural angle 6. 



Description. Shell elongated, slender, whorls numerous; 

 sutures well defined; aperture almost round. Ornamenta- 

 tion consists of four nodular ribs. In the older portion of 

 the spire these ribs are uniformly developed, but in the 

 younger portion of the shell the two middle ribs are larger 

 than those on either side. There are fine lines of growth 

 between the ribs, some of which are larger than others. 



