230 CALIFOENIA ACADEMY OF SCIENCES. 



Pleistocene. — San Pedro to San Diego (Cooper): San Pedro; San Diego 

 (Arnold). 



Genus Macron H. I- A. Adams. 



Shell ovate, solid, with a thick epidermis; spire elevated; columella wrinkled, with a callosity 

 at the upper part; outer lip thin, with a small tooth anteriorly. 



Type, Macron kellettii A. Ads. 



216. Macron kellettii A. Adams. 



Pseudoliva kellettii A. Ad., Proc. Zool. Soc, 1853, p. 185. 



Macron kellettii K. Ad., Cpr., Brit. Assn. Rept, 1863, p. 664. Tryon, Man. Conch., Vol. Ill, 



p. 214, PL LXXXII, fig. 477, 1881. Keep, West Coast Shells, p. 21, 1892. Cooper, 



Bull. No. 4, Cal. St. Min. Bureau, Part 3, 1894, p. 27. 



Shell ovate, solid, subperforate; spire prominent; whorls rounded; suture canal-like; last 

 whorl spirally sulcated; aperture oval ; columella callous posteriorly, anterior portion produced and 

 flexed; posterior part of lip bent, anterior part dentate. Canal a mere notch. Average length 

 about 25 mm. 



One specimen in upper San Pedro series of San Pedro. 



Living. — Lower California (Keep): Catalina Island to Lower California 

 (Cooper). 



Pleistocene. — San Pedro (Arnold) : San Joaquin Bay, Orange County (Bowers). 



Pliocene. — V^entura County (Bowers). 



217. Macron lividus A. Adams. 



Macron lividus A. Ad., Cpr., Brit. Assn. Rept.. 1863, p. 664. Keep, West Coast Shells, p. 20, 

 fig. 2, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 216. 



Shell small, ovate, solid; spire elevated; apex subacute; whorls five, evenly convex, smooth; 

 suture distinct; aperture ovate; outer lip sharp and curved; inner lip short and bent; columella with 

 a strong fold near the top of the aperture. 



Dimensions. — Long. 19 mm.; lat. 10 mm.; body-whorl 14 mm.; aperture 10 mm. 



This species is characterized by its smooth surface and small size. One 

 specimen found in the upper San Pedro series at the lumber yard, San Pedro. 



Living. — San Pedro (Williamson) : San Diego to Lower California (Carpenter). 



Pleistocene. — San Pedro (Arnold). 



Family LIX. NASSID^E. 

 Genus Nassa Lamarck. 



Shell ovate, ventricose; body-whorl variously sculptured; aperture ovate, with a short, reflected, 

 truncated, anterior canal; inner lip smooth; often widely spread over with enamel, with a posterior 

 callosity or a blunt dentiform; outer lip dentated, internally crenulated. 



Nassa mutabilis Linn, is a characteristic species. 



