CRETACEOUS FOSSILS. 115 



CYLINDRITES, Morris and Lycett. 

 C. brevis, n. s. 



PI. 29, Pig. 223. 



Shell short, robust, ovoid; spire low; whorls four, rounded 

 on the upper margin ; suture deep. Aperture broad, produced 

 and rounded in advance ; outer lip simple ; inner lip incrusted ; 

 the incrustation forming a large fold in advance. Sides of the 

 body volution subnattened, approaching anteriorly. Surface 

 marked only by a few indistinct lines of growth. 



Figure, nearly three times natural size. 



Locality : A few specimens have been found by Mr. Mathewson in the vicinity 

 of Martinez. 



This shell is remarkable for its very short, robust form, making an outline dif- 

 ferent from any other species of the genus with which I am acquainted. As far 

 as I am aware, this is the first species discovered in the Cretaceous formation. 



CHEMNITZIA, D'Orb. 

 C. Spillmani, Con. ? 



PI. 10, Fig. 70. 



(C. Spillmani, Con. Jour. Academy of Nat. Sciences Philadelphia, 2 ser., vol. 4, 



p. 287, pi. 4G, fig. 48.) 



Shell elongated, slender; whorls flattened on the sides; suture 

 impressed. Surface marked by slightly curved, obtuse, longitu- 

 dinal ribs, crossed by four or five impressed lines; under surface 

 smooth. Columellar lip thickened. 



Except the difference in size — and this is in all probability a young specimen — 

 I cannot find a single character on which to separate this shell from Mr. Conrad's 

 species. The difference in the apical angle is not so great as would seem, from a 

 comparison of the figures. The sides, in Mr. Conrad's specimen, are much more 

 marly parallel than he has represented them. 



Locality: Pence's Kanch, north of Oroville, Butte County (Division A.): col- 

 lected by Mr. Brewer. 



