ARNOLD -I' HE rALEONTOLOGY AND STRATIGKAPHY OF SAN PEDRO. 279 



[«. D.J Turbonilla (Pyrgolampros) lowei, var. pedroana I). <C- li., var. iiov. 



Pl.ATK II, EuiS. 3 AND ,3a. 



Shell similar to T. Icncci, both in general form and sculpture, but more robust, broader and 

 less attenuate; nuclear \viiorls three, half immersed; post-nuclear whorls with ribs of more uniform 

 size, not crowded and enfeebled on the early wliorls as in T. lowci; basal portion of the whorls of a 

 darker color than the upper, causing the exposed portion of the whorls to apipear baniietl above the 

 suture; whorls faintly shouldered, otherwise as in T. loiuei. 



Dimensions. — Long. 7 mm.; diam. 2.3 mm. 



The type lia^ nine post-nncIear wliorls. SpeciiiieiLS from Victoria, 1>. C, are 

 .still lii-oader. One of seven post-nnclear whorls mca.sures: long. 5.b mm.; diam. 

 "_M mm. Tiie nortliern specimens are also somewhat lighter in color. This variety 

 is found liviiii;- from Victoria, B. C, to 8tin Diego, and occurs fossil in (lie post- 

 Pliocene heds at San Diego. 



298. Turbonilla (Pyrgolampros) arnoldi D. X- B., sp. nov. 



ri..\TE I, Tio. 7. 



Shell whitish, robust, more or less inflated; nuclear whorls decollated; post-nuclear whorls 

 flattened, somewhat contracted at base, and slightly outcurved at the summit, traversed by about 

 twenty-two to twenty-eight more or less irregular a.xial ribs, slanting slightly toward the aperture, 

 and which extend less jjrominently over the well-rounded periphery of the last whorl to the umbilical 

 region; suture deep, subchanneled, somewhat undulate; the entire surface of the whorls is covered 

 with fine, very closely placed, wavy, spiral striations; last whorl somewhat produced; aperture large, 

 subovate, with a thin outer lip, which is decidedly effuse at base, and meets the somewhat oblique and 

 revolute columella in a Inroad curve. 



Ditnensions. — Long. 7.6 mm.; diam. 2.3 mm. 



The specimen figured has eight post-nuclear whorls. 



This species .so far has only been rei)orted from the post-Pliocene deposits 

 of Deadman Island. It is named in honor of Mr. Ralph Arnold, of Pasadena, 

 California. 



299. Turbonilla (Pyrgolampros) gibbosa Carpenter. 



Pi.ATK I, Fii:.s. 2 AND 2a. 



Chcmnitsia gibbosa Cpr., Cat. Maz. Shells, p. 430, No. 525, 1857. 



Shell inflated, robust, broad and stumpy, of light, fulvous coloration; nuclear whorls deeply 

 immersed, very slightly exposed at the tip, their axis apparently being at a right angle to the axis of 

 the later whorls; post-nuclear whorls flattened, somewhat contracted at the periphery and rounded 

 at the summit, traversed by about sixteen to twenty-four broad, coarse, irregularly slanting axial 

 ribs, which extend over the inflated periphery of the last whorl to tiie umbilical region, appearing less 

 promment on the base; the entire surface of the shell is covered by very minute, close, spiral 

 striation; suture subchanneled and wavy; aperture ovate, outer lip thin, joining the twisted and 

 revolute columella in a broad curve. 



Dimetisions. — Long. 5.6 mm.; diam. 2. r mm. 



The specimen figured has seven post-nuclear whorls. 



