MARYLAND GEOLOGICAL SURVEY 661 



Occurrence. KANCOCAS FORMATION. South feeder ISToxontown Pond, 

 Delaware. 



Collection. Maryland Geological Survey. 



Genus TENEA Conrad 

 [Am. Jour. Conch., vol. vi, 1870, p. 72] 



Type. Tenea parilis Conrad. 



" A V-shaped tooth under the apex of the left valve,the anterior lobe 

 of which is continued along the margin anteriorly, forming a long, deep 

 pit above it; one distant very oblique cardinal tooth posterior to the apex. 

 Hight valve: Two cardinal teeth united above; anterior one falcate, with 

 a pit on each side ; posterior one curved and directed obliquely backward." 

 Conrad, 1870. 



The genus in its known distribution is confined to the Cretaceous. 



TENEA PARILIS Conrad 



Mysia (Diplodonte) parilis Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d 



ser., vol. iv, p. 278, pi. xlvi, fig. 16. 



Tenea parilis Conrad, 1870, Am. Jour. Conch., vol. vi, p. 73, pi. iii, fig. 12. 

 Tenea parilis Conrad, 1875, Kerr's Geol. of North Carolina, App., p. 8, pi. ii, 



fig. 25. 

 Tenea parilis Tryon, 1884, Syst. and Struct. Conch., vol. iii, p. 216, pi. cxix, 



fig. 72. 

 Dosinia gabbi Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 161, pi. 



xxii, figs. 4, 5. 

 Tenea pinguis Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 163, pi. 



xxii, figs. 1, 2 (not T. pinguis Conrad). 



Tenea parilis Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 15. 

 Tenea parilis Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, p. 572, 



pi. Ixiii, figs. 1-6. 



Description. " Shell suborbicular, equilateral, ventricose, direct ; sur- 

 face entire ; hinge- with the anterior cardinal channel very profound."- 

 Conrad, 1860. 



Type Locality. Tippah County, Mississippi. 



Shell thin, fragile, ovate in outline, moderately convex, slightly inequi- 

 lateral, lunule and escutcheon not defined ; umbones inflated to their very 



Etymology: Corruption of tenuis, thin. 



