MARYLAND GEOLOGICAL SURVEY 489 



Variable in size and outline, as are all the species of this genus. Inter- 

 mediate forms are frequent, and some approach Sceptroneis gemmata 

 which, also, in some forms is near Sceptroneis caduceus. 



Occurrence.— Cain-ert 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 K. E. Bridge, 1 mile northwest of West River, 

 1 mile east of Marriott Hill. 



CoZZech'on.— Maryland Geological Survey. 



Ehaphoneis amphiceros Ehrenberg. 

 Ehaphoneis fusus Ehrenberg. 

 Ehaphoneis lancettula Grunow. 

 Ehaphoneis linearis (Grunow). 

 Ehaphoneis rhombus Ehrenberg. 

 Ehaphoneis scalaris Ehrenberg. 



Genus SCEPTRONEIS Ehrenberg. 



Sceptroneis caduceus Ehrenberg. 

 Plate CXXXV, Fig. 12. 



Sceptroneis caduceus Ehrenberg, 1844, Monatsb. d. k. Akad. d. V\^iss., Berlin, p. 264. 

 Sceptroneis caduceus Ehrenberg, 1856, Mikrogeologie, pi. 38, xvii, fig. 15. 

 Sceptroneis caduceus Van Heurck, 1881, Syn. Diat. Belg. pi. xxxvii, fig. 5. 



Description.— ValYe lanceolate, larger at the middle and usually with 

 one end more or less capitate. Surface with rounded granules in trans- 

 verse lines. L. of v. .122 mm. 



This species is variable in size and outline and appears to pass into 

 S. gemmata. 



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 Mar- 

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



