NO. 6 OYSTERS OF THE LOPHA LUGUBRIS GROUP — KAUFFMAN 85 



Fig. 2. Lateral view of a left valve, abnormally short owing to reduced 

 posterior auricle ; a hypotype from the upper Eagle Ford Shale, 2.5 miles 

 east of Eagle Ford, Dallas County, Tex. (locality 15, U.S.G.S. 7539) ; 

 U.S.N.M. 132214. 



Fig. 4. Lateral view of a left valve with reduced posterior auricle, unusually 

 large attachment scar and prominent umbo; a hypotype from the upper 

 Eagle Ford Shale of Texas (locality 15, U.S.G.S. 7539, cited above) ; 

 U.S.N.M. 132216. 



Fig. 5. Lateral view of a worn left valve with unusually large smooth stage ; 

 a hypotype from the Eagle Ford Shale at Sherman, Tex. (locality 54), 

 the original of Stanton's plate 4, figure 8 (1893) ; U.S.N.M. 11882a. 



Fig. 6. Lateral view of a left valve with unusually large attachment scar; 

 posterior auricle broken; a hypotype from the upper Eagle Ford Shale, 

 Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited above) ; U.S.N.M. 

 132217. 



Fig. 7. Lateral view of an abnormal left valve ; note unusual height, reduction 

 of auricles, broad plicae, a hypotype from the upper Eagle Ford Shale, 

 Dallas County, Tex. (locality 57) ; U.S.N.M. 132218. 



Fig. 8. Lateral view of an unusual left valve with broad plicae, fluted at 

 their intersection with coarse concentric lamellae, and abnormally large 

 smooth umbonal area. This form is possibly transitional to Lopha panda 

 (Morton). A hypotype from the upper Eagle Ford Shale, Dallas County, 

 Tex. (locality 15, U.S.G.S. 7539, cited above) ; U.S.N.M. 132219. 



Fig. 10. Lateral view of a typical left valve with abnormally projecting beak 

 and early umbo; a hypotype from the upper Eagle Ford sands, 1.75 miles 

 west of Sherman, Tex. (locality 50, U.S.G.S. 14553) ; U.S.N.M. 132221. 



Fig. 12. Lateral view of a left valve, unusual in having a nearly centrally 

 situated beak and broad plicae; a hypotype from the upper Eagle Ford 

 Shale, Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited above) ; 

 U.S.N.M. 132223. 



Fig. 13. Lateral view of White's hjpotype (1879, pi. 4, figs. 3a, b) from the 

 Eagle Ford Shale at Denison, Tex. (locality 56) ; U.S.N.M. 12383. 



Fig. 14. Lateral view of a typical adult left valve; a hypotype from upper 

 Eagle Ford sands, 1.75 miles west of Sherman, Tex. (locality 50, U.S.G.S. 

 14553) ; U.S.N.M. 132224. 



Fig. 16. Lateral view of an unusually elongate, high left valve, more inclined 

 than normal, and with a large attachment scar; a hypotype from Dallas 

 County, Tex. (locality 57) ; U.S.N.M. 132226. 



Fig. 17. Lateral view of a typical left valve with an unusually large attach- 

 ment scar, a hypotype from the upper Eagle Ford Shale, 2.5 miles east of 

 Eagle Ford, Dallas County, Tex. (locality 15, U.S.G.S. 7539, cited 

 above) ; U.S.N.M. 132227. 



Plate 4 



(All figures XI) 



Lopha bellaplicata hellaplicata (Shumard) 



Fig. 1. Lateral view of a left valve from White's syntype lot of Lopha blacki. 

 Note that other than the projecting beak and umbo, deformed by the 



