Maryland Geological Survey 489 



vertebroides. The second in front of the posterior suture is usually a 

 little stronger than the rest and in the immature individuals the first 

 spiral in front of the posterior suture is feehle or undeveloped. 



Turritella paravcrtcbroides is apparently the analogue in Maryland of 

 the abundant and characteristic vertebroides of the Gulf and New Jersey. 

 It differs most conspicuously from Morton's well-known species in the 

 more subdued sculpture. The primary spirals are never so sharply ele- 

 vated, and, unlike vertebroides', they are relatively more prominent upon 

 the posterior portion of the whorl. The secondary sculpture is finer and 

 more regular, the whorls are less constricted at the sutures, the periphery 

 of the body is not acutely carinated, nor is it outlined by a prominent 

 spiral, and the base is striated though faintly so. Weller ' figured a second 

 specimen which has not been described, apparently, although it is widely 

 distributed, not only through New Jersey but the Gulf as well. From this 

 unnamed form T. paravertebr aides differs in its rather larger size, more 

 flattened whorls, sculptured apical region, the broader primaries with 

 numerous intercalated secondaries and a less strongly lirated base. 



Occurrence. — Monmouth Formation. Brightseat, Brooks estate near 

 Seat Pleasant, Prince George's County. 



Collection. — Maryland Geological Survey. 



Turritella trilira Conrad 



Turritella trilira Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. iv, 



p. 285. 

 Turritella corsicana Shumard, 1861, Proc. Bost. Soc. Nat. Hist., vol. viii, 



p. 196. 

 Turritella corsicana Meek, 1864, Check List Inv. Fossils, N. A., Cret. and 



Jur., p. 18. 

 Turritella trilira Meek, 1864, Ibidem. 

 Turritella trilineata Hill, 1901, 21st Ann. Rept. U. S. Geol. Survey, pt. vii, 



pi. xlvii, fig. 3. 

 Turritella trilira Veatch, 1906, Prof. Paper U. S. Geol. Survey, No. 46. pi. 



xi, fig. 4. 

 Turritella trilira Weller, 1907, Geol. Survey of New Jersey, Pal., p. 899, pi. 



lxxix, figs. 4, 5. 



1 Rept. Cret. Pal. New Jersey, 1907, vol. iv, pi. lxxviii, fig. 14. 



