414 Systematic Paleontology 



elevated and broadly convex; external surface cancellated, axial sculpture 

 of about fifteen narrow, rounded, sharply pinched costals separated by 

 wider concave intercostals ; axials tending to become irregular and to 

 evanesce upon the final half turn and upon the base of the pillar ; axials 

 overridden by narrow, flattened, equi sized and equispaced spiral fillets, 

 uniform in character upon the costal and intercostal areas, separated by 

 channeled interspaces, slightly wider than the spirals; primaries four in 

 number upon the penultima and five or six on the ultima ; two or three 

 secondaries developed upon the shoulder and three or four at the base of 

 the body; body whorl evenly rounded anteriorly; aperture holostomous, 

 ovate to lenticular, outer lip thin, simple, broadly arcuate ; inner lip exca- 

 vated at the base ; aperture constricted at its anterior extremity to form an 

 incipient canal ; parietal wall calloused ; umbilicus closed by the reverted 

 labium ; area directly behind it feebly depressed. 



Conrad's description implies a perforate shell, but there has been not 

 even a chink of an umbilical opening in any of the numerous individuals 

 examined from the Gulf as well as from Maryland. 



Paladmete cancellaria is widely distributed through the Monmouth of 

 the Gulf and the Middle Atlantic Coast. 



Occurrence. — Monmouth Formation. One-half mile east of Millers- 

 ville, Anne Arundel County ; Brightseat, 1 mile west of Friendly, Prince 

 George's County. 



Collections.- — Maryland Geological Survey, U. S. National Museum. 



Outside Distribution. — Ripley Formation. Exogyra costata zone, Union 

 and Tippah counties, Mississippi. 



Family TURRITIDAE 



Genus TURRIS Bolten 

 [Mus. Bolt., 1798, p. 123] 



Turris anon., 1797, Mus. Calonnianum, pp. 34, 82; nude name, including 

 Turris babylonius. 



Pleurotoma Lamarck, 1799, Prodrome, p. 73; sole example Mures baby- 

 lonius Linne. 



Turris Dall, April, 1906, Jour. Conch. (Leeds), vol. xi, p. 291. 



Turris Dall, 1909, Prof. Paper U. S. Geol. Survey, No. 59, p. 24. 



Etymology: Turris, tower. 



