— 28 — 



Quat. — Dead Man's Island, San Pedro Bay (Mrs. M. B. Williamson). 



Carpenter describes this shell, but gives it as named by A. Adams. 

 No reference to Adams' works is given. Identified by Mr. Dall, from 

 types. 



Note. — The locality for the fossil shell quoted in the Catalogue of 



Fossils, 1888, "San Marcial." cannot be found in California. Such a 



place is on the peninsula, east side, near latitude 25° 30', where fossils 



were collected by Aug. Remond, and is in the belt of Tertiary according 



to Gabb. 



Modiola modiolus Linne. 



Syst. Nat., No. 1158. Binney, Gould's Moll, of Mass., p. 186, f. 485. 



Living — Circumboreal, south to San Pedro in Calif. 

 Mioc. — Ventura County (S. Bowers). 



Monoceros lapilloides Conrad. 



Jour. Acad. Nat. Sc. Phil, VII, 1837, p. 265, pi. 20, f. 18. Keep, 



Common Shells, p. 19, pi. Ill, f. 1. 

 Living — Monterey to Santa Barbara. 

 Quat. — Ventura County (Bowers). 



Murex radix Gmelin (var. nigritus, Phillipi). 



Syst. Nat., p. 3527, No. 10. Reeve, Con. Icon. Murex, pi. 17, f. 69, 



1845. Phil., Abbild., 1845, p. 1, pi. 1. Carp., Mazat. Shells, p. 521, ' 



525 {M.princeps Brod., 1832). 



The Rev. J. Rowell compared the specimens with a large series of 

 the above forms from west tropical America, and considers them 

 between nigritus and princeps. They doubtless represent an ancestral 

 form, now more or less divided into sub-species. M. radix was also 

 found fossil by H. Hemphill, in Southern or Lower California. 

 (Catal. of N. Amer. Shells, 1890.) 



Living — Margarita Bay, Lower California, to Panama (and South 

 America?). 



Mioc. — Foothills of Orange County at over 1,000 feet elevation (S. 

 Bowers). 



Murex trialatus Sowerby? (not of Kiener or of other authors). 



The synonymy is very unsettled. Not found in tropical America? 



Living — San Diego and southward. Determined by Mr. Dall. 



PL — Ventura (S. Bowers). Except in absence of a spur, smaller 

 mouth, and various color-bands, this shell does not differ much from 

 Pterorhytis foliatus, and may be only a southern variety of that varia- 

 ble shell. 



