MARYLAND GEOLOGICAL SURVEY 507 



Distinguished from C. apiculatus by its more evident central dots, 

 its narrow border and larger central space. In its size and the character 

 of its markings the two are often similar. 



Occurrence. — Calvert Formation. Flag Pond, | mile south of Par- 

 ker Creek, 3 miles north of Parker Creek, Plum Point, | mile north of 

 Forest Wharf, Xomini Bay, Chesapeake Beach, God's Grace Point, Fair- 

 haven, 1 mile west of Tracy Landing, 1^ miles southeast of Marriott 

 Hill, 1 mile north of Jewell, 1 mile north of Jones Point, 1 mile south 

 of Chesapeake R. E, Bridge, 1 mile northwest of West River, 1 mile east 

 of Marriott Hill. 



Collection. — Maryland Geological Survey. 



