MAItVI.ANI) (iKOI.OCIC \r. sritVKY 159 



The figured specimen (besides which only Iragnients have been found) 

 is strongly and regularly compressed in {\w plane at right angles to that 

 of curvature. So natural does the compression appear that the indi- 

 vidual was referred to the genus (Jompreftsidens of Pilsbry. Ikit other 

 fragments have hccn I'lMiml wliidi have a iirrlVctlv round aprrturr. and 

 faint cracks have been discovered along the lines of greatest curvature 

 of the compressed specimen, and therefore the character must probably 

 be regarded as accidental. 



Length. IT nun.; width, 1.T5 \ "i..") niiii. (flattened). 



Occurrence. — Xaxjemoy Formation. Popes Creek. 



Collection. — jMarvlaiul Geological Survey. 



DentaliuiM MississiPPiEXSis Conrad. 

 Plate XXIX, Fig. 8. 



Deutnlium mis/tissippiensis Conrad, 1848, .Jour. Acad. Nat. Sci. Pliila., '2i]d Ser., vol. 

 i, p. 112, pi. xi, tig. 1. 



Description. — '^ Curved, attenuated above, longitudinally striated, the 

 lines alternating in size. ... It differs from D. tlialloides in having 

 more numerous and much less prominent lines.'' Conrad, 1848. 



Length, 36 mm.; viddth, 6 mm. 



Occurrence. — Xanjemoy Foematiox. West of Port Tobacco, 1 mile 

 southeast of Piscataway. Aquia Formatiox'. Upper Marlboro. 



Collection. — ^Maryland Geological Survey. 



Family SIPHONODENTALIIDAE. 



Genus CADULUS Philippi. 



Cadulus abruptus Meyer and Aldrich. 



Plate XXIX, Fig. 9. 



Cnflnlm dbriiptua Meyer autl Aldricli. 1SS7, .Jour. Cin. Soc. Nat. ITist., vol. ix, No. 2, 



p. 40, pi. ii, tig. 2. 

 Cadulus bellulus Clark, 180.5, Johns Hopkins Univ. Circ., vol. xv, p. h. 

 Cachilus belhchis Clark, 1S96, Bull. 141, U. S. Geol. Survey, p. 72. pi. xiv, fig. 6. 



Description. — "Eather large, somewhat depressed. Inflation very 

 near to the larger aperture and suddenly decreasing." Me5'er and Al- 

 drich. 1886. 



