MARYLAND GEOLOGICAL SURVEY 



491 



the margin. The valves differ from each other in convexity and in 

 the nearness of spine to the margin. Diam. .072 mm. 



Occurrence.— CAi^YmT Formation. Flag Pond, f mile south of 

 Parker Creek, 3 miles north of Parker Creek, Plum Point, ^ mile north 

 of Forest Wharf, Nomini Bay, Chesapeake Beach, God's Grace Point, 

 Fairhaven, 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 E. E. Bridge, 1 mile northwest of West Eiver, 1 mile east 

 of Marriott Hill. 



Collection. — Maryland Geological Survey. 



Stephanopyxis limbata Ehrenberg. 

 Stebhanopyxis turris (Greville). 



Genus PARALIA Heibeig. 



Paralia SULCATA (Ehrenberg). 



Plate CXXXV, Fig. 9. 



Gallionella sulcata Ehrenberg, 1840, Abhand. BerL Akad., pL iii, fig. 5. 



Melosira sulcata Kutzing, 1844, Bacill. p. 55, pi. ii, fig. 7. 



Gallionella sulcata Ehrenberg, 1856, Mikrogeologie, pi. 33, siv, fig. 13 ; xvi, figs. 12, 



15. 

 Orthosira marina Wm. Smith, 1856, Brit. Diat., vol. ii, p. 59, pi. liii, fig. 338. 

 Paralia sulcata Cleve, 1894, Arctic Diat., p. 7. 

 Paralia sulcata Schmidt, 1875, Atlas der Diatomaceen-kunde, pi. clxxvi, figs. 35- 



37, 39. 

 Melosira sulcata Van Heurck, 1881, Syn. Diat. Belg., pi. xci, figs. 16-18. 



Description.— Valves circular, the frustule attached in cylindrical 

 filaments. Border of valve coarsely cellular, the central part depressed 

 with delicate strise covering from the ring forming the Junction of the 

 frustules, but not always reaching the center. Diam. .049 mm. (av). 



Extremely abundant in all deposits. Occurs living and in fossil 

 deposits in all parts of the world, especially in the Miocene. 



Occurrence. — Calvert Formation. Flag Pond, f mile south of 

 Parker Creek, 3 miles north of Parker Creek, Plum Point, ^ mile north 

 of Forest Wharf, Nomini Bay, Chesapeake Beach, God's Grace Point, 

 Fairhaven, 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 E. E. Bridge, 1 mile northwest of West Eiver, 1 mile 

 east of Marriott Hill. 



Collection. — Maryland Geological Survey. 



