NO. 1569. WEST AMERICA.^ MOLLUSKS—BARTSCH. 251 



the last whorl ornamented by a tubercular keel, which is not quite as 

 strong as the supraperipheral keel. Base dark brown, moderately 

 long, marked by two strong spiral keels, the anterior one of which is 

 situated partly upon the columella, while the other one occupies a 

 plane half way between the anterior and the peripheral keel. The 

 spaces which separate these keels are about equal in width and are 

 crossed by slender continuations of the axial riblets. Columella stout 

 and twisted, marked by slender spiral lirations. Aperture pyriform, 

 strongly channeled anteriorly and posteriorly; outer lip patulous, 

 marked within by a light brown band posteriorly and a narrow dark- 

 brown zone at the base; columella and parietal wall covered with a 

 thick callus. 



The above description is based upon two specimens, cotypes. Cat. 

 No. 152206, U.S.N. M. An adult individual, from San Pedro, Califor- 

 nia, has furnished the description of the adult features. It has lost 

 the nuclear whorls. The eight which remain measure: Length, 5.1 

 mm.; diameter, 1.9 mm. Cat. No. 56910, U.S.N.M., a juvenile speci- 

 men, collected by Dr. W. H. Dall, at Catalina Island, California, has 

 furnished the description of the nuclear and early post-nuclear turns. 

 It has four nuclear whorls and seven and one-half post-nuclear turns, 

 and measures : Length, 3 mm. ; diameter, 1 .35 mm. A third specimen, 

 Cat. No. 56017, U.S. N.M., was collected by Doctor Dall at San Diego, 

 California. A fourth was coUected by Mr. F. W. Kelsey among rocks 

 in sand and gravel at low tide at Ocean Beach, California. Three 

 fossil specimens from the Upper San Pedro Series, at the lumber yard, 

 San Pedro, California, were examined in Mr. Delos Arnold's collection. 



TRIPHORIS CALLIPYRGUS, new species. 



Plate XVI, lig. 4. 



Shell elongate, conic, subturrited, uniformly light brown. (Early 

 whorls decollated.) The remaining seven are separated by strongly 

 impressed sutures, and are ornamented with three 'spiral tuberculate 

 keels on the spire. The middle one of these keels is decidedly 

 stronger than the rest and marks the widest part of the turns, while 

 the anterior one is the least developed on all the early turns. On the 

 last whorl the three are subequal. In addition to the spiral keels the 

 spire is marked by slender, axial riblets, of which there are about 

 eighteen upon the first of the remaining and twenty upon the penul- 

 timate turn, the intersection of the riblets and the spiral keels form- 

 ing the tubercles. The tubercles slope convexly toward their anterior 

 limit and are somewhat excavated posteriorly. Periphery of the last 

 whorl marked by a sulcus. Base with two equally strong keels on 

 the posterior half, sejiarated from each other by a sulcus as wide as 

 the peripheral one, and a third weak thread on the base of the thick 



