A COXTRIBUTIOX TO THE LOAVER DeVOXIAX FaUXAS OF MaRYLAXD 23 



Section DYSODONTA 



Superfamily MYTILACEA 

 Family MODIOLOPSIDAE 



Genus MEGAMBONIA Hall 



Megambonia lamellosa Hall 



Plate LXXYIII, Fig. 5 



Megambonia lamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. ill, p. 467, pi. cix, 

 figs, 5, 6, 1861. 



Description. — " Shell obliquely ovoid, very gibbous in the middle and 



towards the umbo ; the body of the shell rather abruptly narrowed above 



the middle. Anterior wing short, rounded, very convex, separated from 



the body of the shell by a broad rounded depression, leaving a sinus in the 



margin. Posterior wing broad triangular, extending more than two-thirds 



the entire length of the posterior slope ; its junction with the body of the 



shell marked by a depression. Surface marked by concentric lamellose 



strise, which, on some parts of the specimens, are very prominent. Faint 



remains of radiating striae are sometimes perceptible on the casts." Hall, 



1859. 



It has been found only in the form of casts, but it is not uncommon in 

 the Oriskany of Maryland. 



Length about 3.5 cm.; height 2.5 cm. 



Occurrence. — Oriskany Formation, Ridgelt Member. Queen's 

 Point opposite Keyser, Miller's Spring, and Knobly Mountain, West 

 Virginia; near Cumberland, Hancock, Maryland. 



Collections.— MsLvylSind Geological Survey, U. S. National ]\Iuseum. 



Order TELODESMACEA 



Superfamily CYPRICARDIACEA 

 Family PLEUROPHORIDAE 



Genus CYPRICARDINIA Hall 



Cypricardixia sublamellosa Hall 



Plate LXXVIII, Fig. 8 



Cypricardinia sublamellosa Hall, 1859, Nat. Hist. N. Y., Pal., vol. iii, p. 267, 

 pi. i, fig. 1, 1861. 



