230 SYSTEMATIC PALEONTOLOGY 



Occurrence. — Calvert Formation. Plum Point, Chesapeake Beach. 

 Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Cornell University. 



Cerithiopsis subulata (Montagu). 

 Plate LY, Fig. 8. 



Murex siibulatus Montagu, 1808, Test. Brit. Suppl., p. 115, pi. xxx, fig. (5. 

 Cerithiopsis {Eumeta ?) subulata Dall, 1889, Bull. Mus. Comp. Zool. Har., vol. xviii, 



p. 25'i, pi. XX, tig. 4. 

 Cerithiopsis {Eumeta) subulata Dall, 1893, Trans. Wagner Free Inst. Sci., vol. iii, 

 pt. ii, p. 268. 



Description. — Shell small, pyramidal, twelve-whorled ; whorls with two 

 large and two small revolving ribs alternating in position, spire wound 

 on the lower and smaller rib half concealing it; larger ribs with twenty- 

 two large regular nodes ; smaller rib between the two larger ones obsolete 

 except on the later whorls; base smooth; canal short, sharply bent. 



This species occurs very abundantly at Greensboro. The specimens 

 have a very close resemblance to those from the Caloosahatchie river. 



Lengih, 8 mm. ; diameter, 2.5 mm. 



Occurrence. — Choptank Formation. Greensboro. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



Family PLEUROCERATID/E. 



Genus GONIOBASIS Lea. 



GONIOBASIS marylandica n. sp. 



Plate LV, Fig. 9. 



Description. — Shell thin, five-whorled; spire pyramidal, wound slightly 

 below the shoulder of the whorl ; sutures distinct but not deep ; surface 

 marked by low, narrow revolving ribs with much wider interspaces; 

 revolving ribs about twelve on the body whorl and five on each whorl 

 of the spire; lines of growth irregular; mouth large, widest below; colu- 

 mella concave; labium callous and marked by faint longitudinal stria- 

 tions. A single specimen of this interesting form has been obtained. 



Length, 15 mm. ; diameter, 6.5 mm. 



Occurrence. — St. Mary's Formation. St. Mary's Eiver. 



Collection. — Maryland Geological Survey. 



