MARYLAND GEOLOGICAL SURVEY 20-1 



Description. — "This fine siDecies lias, like most of the species of this 

 genus, only four varices. The spire is much shorter than in M. umhrifer 

 and the form of the varices is different."' Dall, 1890. 



Shell of moderate size, very solid, five-whorled ; varices four, broad, 

 thick, reflexed, intervarical spaces with low, rounded, revolving ribs, and 

 distant obscure lines of growth ; central part of the whorl strongly cari- 

 nated ; face of the last varix with wavy lines caused by the edges of the 

 laminae; umbilicus small; canal barely closed, slightly reflexed. 



Length, 36 mm. ; diameter, 25.5 mm. 



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



Collection. — U. S. National Museum. 



Genus TYPHIS Montfort. 



Typhis acuticosta Conrad. 

 Plate LI, Figs. 1, 2, 3. 



Murex acuticoiita Conrad, 1S30, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st ser., pp. 



311, ai7, pL ix, tig. 1. 

 Typhis acuticosta Conrad, 1842, Proc. Nat. Inst., Bull, ii, p. 187. 

 Typhis acuticosta Conrad, 1801, Fossils of the Medial Tertiary, No. 4, p. 83, pi. 



xlviii, tig. 1. 

 Typhis acuticosta Conrad, 1S63, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 5ti0. 

 Typhis acuticosta Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 22. 

 Typhis acuticostata Conrad, 1868, Amer. Jour. Conch., vol. iv, p. 64, pi. v, tig. 6. 

 Typhis acuticosta Dall, 1890, Trans. Wagner Free Inst. Sci., vol. iii, pt. i, p. 151. 

 3Inre£ acuticostata Harris, 1893, Amer. Jour. Sci., ser. iii, vol. xlv, p. 30. 



Description. — " Shell with four or five acute foliated varices ending 

 above in a pointed, compressed spire, alternating with four shorter 

 rounded varices ending above in a tube ; aperture oval and entire ; margin 

 reflected; beak closed, and slightly recurved." Conrad, 1830. 



Length, 21 mm.; diameter, 11 mm. 



The form from Plum Point may be a distinct variety or species. It is 

 very elongate, having a six-whorled spire and long spines and canal. 



Length, 18 mm.; diameter, 8.5 mm. 



Occurrence. — St, Mary's Formation. St. Mary's Eiver, Cove Point, 

 Langley's Bluff. Choptank Formation. Jones Wharf, Calvert For- 

 mation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Philadelphia Academy of Natural Sciences, Cornell University, U. S. 

 National Museum. 



