MARYLAND GEOLOGICAL SURVEY 143 



main fossiliferous beds instead of two as earlier described, viz., Lower 

 Shell bed, Serpula bed, Upper Shell bed and Fragment bed. The first 

 and second, according to Cushman, show faunas of southern relations, 

 while the third and fourth show faunas of northern relations, a conclu- 

 sion which largely substantiates the earlier views of Professor Verrill. 

 The common forms of the lower beds are for the most part unusual in 

 the upper beds, and of the twenty-six new forms introduced in the latter, 

 twenty-four of them are southern. 



Still more recently Fuller 8 has correlated the fossiliferous beds with 

 deposits on the islands farther to the westward and has discussed their 

 interglacial origin and stratigraphic relations. 



The following species common to the Maryland Pleistocene have been 

 recognized in the early fauna of the lower beds at Sankoty Head : Bala- 

 nus crenatus Brugniere, Nassa trivittata Sa,j, Ilyanassa obsoleta 

 (Say), Columbella (Astyris) lunata (Say), Ewpleura caudata (Say), 

 Urosalpinx cinereus (Say), Turbonilla (Pyrgiscus) interrupta (Totten), 

 Crepidula fornicata (Linne), Crepidula plana Say, Corbula contracta 

 (Say), My a arenaria Linne, Ensis directus (Conrad), Cumingia telli- 

 noides (Conrad), Tellina tenera Say, Petricola pholadiformis Lamarck, 

 Venus mercenaria Linne, Mytilus (Hormomya) hamatus Say, Ostrea 

 virginica G-melin, Area (Noetia) ponderosa Say, Area (Scapharca) trans- 

 versa Say, Cliona sulphurea (Desor) Verrill. 



The late fauna of the upper bed has afforded the following species : 

 Nassa trivittata Say, Ilyanassa obsoleta (Say), Urosalpinx cinereus 

 (Say), Odostomia impressa Say, Crepidula fornicata (Linne), Crepi- 

 dula plana Say, Polynices (Neverita) duplicatus (Say), Mya arenaria 

 Linne, Ensis directus (Conrad), Macoma balthica (Linne), Venus mer- 

 cenaria Linne, Ostrea virginica Gmelin, Area (Scapharca) transversa, 

 Say. 



Farther to the south at Gardiner's Island, New York, and in the vi- 

 cinity of New York city a number of characteristic Pleistocene fossils 

 have been found. Among the Maryland forms are 9 : Nassa trivittata 



8 Bull. Geol. Soc. Amer., vol. xvi, pp. 386-389, 1905. 



9 Packard, Memoirs Boston Soc. Nat. Hist., vol. i, p. 251, 1866; Verrill, Amer. 

 Jour Sci. 3d ser., vol. x, pp. 370-374, 1875. 



