MARYLAND GEOLOGICAL SURVEY 181 



pressed lines on the body whirl, and a somewhat more conspicuous groove 

 near the summit of each volution; spire as long or longer than the body., 

 and with a rufous revolving line near the suture; body whirl trilineate 

 with rufous, the lines placed one near the suture, one on the middle, and 

 the third rather darker, at the- origin of the beak; suture regular and 

 deeply impressed; beak distinguished by a profound depression, from the 

 body whirl, slightly reflected; labrum not incrassated, with raised lines 

 within upon the fauces which do not extend quite to the edge of the lip ; 

 labium distinctly lamellar, with an obsolete fold of the basal edge, and 

 a tooth near the superior junction with the labrum." Say, 1822. 



This is one of the most common and characteristic species in the Mary- 

 land Pleistocene. It has been frequently confounded with Nassa peralta 

 Conrad of the Miocene, and it is probable that the repeated listing of 

 this form from the Miocene of Maryland is erroneous. The earliest au- 

 thentic representatives of this species come from the Pliocene of North 

 Carolina (Croatan Beds of the Neuse Eiver). It is common in the 

 Pleistocene from Massachusetts to South Carolina, and is found in the 

 Eecent ranging from Nova Scotia to Florida. 



Length, 17 mm.; width, 9 mm. 



Occurrence. — Talbot Formation. Wailes Bluff near Cornfield Har- 

 bor, St. Mary's County. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 and U. S. National Museum. 



Genus ILYANASSA Stimpson. 



Ilyanassa obsoleta (Say) 



Plate XLIX, Figs. 3, 4. 



Nassa obsoleta Say, 1822, Jour. Acad. Nat. Sci. Phila., vol. ii, 1st ser., p. 232. 

 Buccinum obsoletum Holmes, 1859, Post-Pi. Fos. S. C, p. 72, pi. xii, fig. 1. 

 Nassa (Ilyanassa) obsoleta Dall, 1889, Bull. U. S. Nat. Mus., No. 37, p. 116, 



pi. 1, fig. 9. 

 Ilyanassa obsoleta Dall, 1890, Trans. Wagner Free Inst. Sci., vol. iii, pt. 2, 



p. 239. 



