392 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 40. 



whorls. Periphery of the last whorl marked by a slender, smooth 

 cord, the space between which and the first supraperipheral cord is 

 about as wide as that which separates the next two cords posteriorly 

 and is crossed by the continuations of the axial ribs which terminate 

 at its posterior border. Base marked by five subequally spaced spiral 

 cords, of which the strongest is immediately below the periphery and 

 is equal to the peripheral cord, while the next two in strength are at 

 the columella; the two intervening are slender threads. Entire sur- 

 face of spire and base crossed by numerous, rather strong lines of 

 growth. Aperture broadly oval, decidedly channeled anteriorly; 

 posterior angle obtuse; outer lip rendered sinuous by the external 

 sculpture; columella short, somewhat twisted, curved and reflected; 

 parietal wall covered with a thick callus. 



Doctor Carpenters cotypes, four specimens (Cat. No. 14823, 

 U.S.N.M.), come from Monterey and Santa Barbara, California. 

 The best preserved has seven post-nuclear whorls and measures: 

 Length 7.3 mm., diameter 2.5 mm. 



Specimens examined. 



Catalogue 

 No. 



14S23 

 56010 

 32396 

 32394 

 56851 

 50004 

 56377 

 56016 

 56681 

 195166 

 105487 

 32302 



Locality. 



Monterey and Santa Barbara, California . 



....do..' 



Monterey Harbor, California 



Monterey, California 



do 



.do. 

 .do. 



North side of Catalina Island, California (15 fathoms, gravel). 



San Miguel Island, California 



San Pedro Bay, California 



San Diego, California 



West Coast 



Number of 

 specimens. 



BITTIUM (SEMIBITTIUM) VANCOUVERENSE Dall and Bartsch. 



Plate 53, fig. 3. 



Bit Hum vancouverense Dall and Bartsch, Dominion Geol. Survey, Memoir No. 

 14 N, 1910, p. 10, pi. 1, fig. 8. 



Shell elongate-conic, grayish white outside and dark, purplish 

 brown within. Nuclear whorls at least two, apparently smooth, 

 worn in all specimens. Post-nuclear whorls slightly rounded, 

 ornamented with three strong, equal, and equally spaced, nodulose, 

 spiral keels, the first of which is a little below the summit. The spaces 

 separating the spiral keels are of equal width. Immediately below 

 the third keel is a strong, peripheral sulcus, which equals those be- 

 tween the spiral keels. In addition to the spiral sculpture, the whorls 

 are marked by almost vertical, axial ribs which are not quite as wide 

 as the spiral keels. These render the keels nodulose at their inter- 

 sections. Of these ribs, 12 occur upon the first, 14 upon the second 

 and third, 16 upon the fourth, 18 upon the fifth, 24 upon the sixth, 

 and 30 upon the penultimate turn. The spaces inclosed between the 

 spiral keels and the axial ribs are well-impressed, rounded pits. AH 



