364 CRETACEOUS PALEONTOLOGY. 



.'-t 



Sub-family MAGELLANINAE. 



Genus TEREBRATELLA d'Orbigny. 



Terebratella plicata (Say). 



Plate XX VII., Figs. i-ii. 



1820. Terebratula plicata Say, Am. Jour. Sci. ist ser., vol. 2, 



P- 43- 

 1829. Terebratula plicata Say, Jour. Acad. Nat. Sci. Phil., ist 



ser., vol. 6, p. 73, pi. 3, figs. 5-6. 

 1834. Terebratula Sayi Mort, Synop. Org. Rem. Cret. Gr. 



U. S., p. 71, pi. 3, %s. 3-4. 

 1845. Terebratula Sayi Mort., Am. Jour. Sci. ist ser., vol. 48, 



p. 283. 

 1861. Terebratella plicata Gabb, Synop. Moll. Cret. Form., p. 



249 (I93)- 

 1864. Terebratella plicata Meek, Check List Inv. Foss. N. A., 



Cret and Jur., p. 5. 

 1868. Terebratella plicata Con., Cook's Geol. N. J., p. 375, 



figure; p. 723. 

 1870. Terebratella plicata Credner, Zeitsch. d. Deutsch. Geol. 



Gessell., vol. 22, p. 224. 

 1886. Terebratella plicata Whitf., Pal. N. J., vol. i.(Monog. 



U. S. G. S., vol. 9), p. 12, pi. i, figs. 5-9. 

 1905. Terebratella plicata Johns., Proc. Acad. Nat. Sci. Phil., 



1905, p. 6. 



Description. Shell subcircular or subovate in outline, pointed 

 posteriorly and rounded in front, strongly plicated, each valve 

 marked by from 8 to 12 or more sharply angular plications 

 which extend to the beak; usually a little wider than long 

 but sometimes longer than wide; the dimensions of four speci- 

 mens are: length, 14.5 mm., 15.5 mm., 19 mm., 17.5 mm.; 

 width, 1 6 mm., 15 mm., 20 mm., 16.3 mm.; thickness, 8 mm., 

 9 mm., 10 mm., 9.5 mm. Pedicle valve strongly convex, with 

 a small, nearly erect beak ; cardinal area of moderate size, sharply 

 defined, slightly concave, with a broad delthyrium partially closed 



