.Makylaxd Geological SruvEV G7d 



This interesting shell constitutes one of the characteristic members of 

 the Naples fauna of New York, where, so far as known, it prevails in 

 the Naples subprovince of the Genesee province; that is, it occurs with 

 frequency in the rocks from Ontario County westward to the Genesee 

 River, but is seldom found in localities further west (Chautauqua sub- 

 province). In a single instance the shell has been found in the higher 

 sands of Ontai'io County after the introduction of the Ithaca fauna. 

 Its occurrence in ^Maryland associated with species which are distinctively 

 of the Chemung assemblage is worthy of special note. The few specimens 

 seen are too illy preserved for illustration but their characters are unmis- 

 takable. 



Occurence. — Jexxixgs Formatiox, CiiEiirxo ME:\iBi:r!. From loose 

 blocks of light yellow friable sandstone near Deer Park Station. A 

 number of species are found in the material reported from these blocks 

 but it is not certain that all represented the same position in the strata. 

 With T. lyrcecursor, however, are found Schizodus, Tcntaculites spiculus, 

 Eciomaria ecclesice, Lepfodesma IdUf/ispinnni and probably Spirifer dis- 

 junctus. 



Collecfioii. — ^Maryland Geological Survey. 



Family LITTORINIDAE 



Genus HOLOPEA Hall 

 HOLOPEA 1?()WEI n. Sp. 



Plate LXIX, Figs. 17, 18 



Description. — This species attains larger dimensions than IT. monj- 

 landica, the slope from the liody whorl upward is mucli more gradual, 

 the spire higher and more elongate. Volutions o-G. The body whorl is 

 not ventricose but highly convex and broad, measuring in vertical diam- 

 eter considerably more than the length of the spire. Internal easts show 

 a deeply excavated suture which is not evident in external casts. An 

 average specimen has a height of 25 mm. and basal diameter of 20 mm. 



The specific name of this shell is intended to commemorate the brief 

 but important services to Marjdand geology of the late Dr. Richard Bur- 



