468 



CALIFORNIA ACADEMY OF SCIENCES 



[Proc. 4th Ser. 



Formation doubtful, Deadman Island, San Pedro, Cal- 

 ifornia ( !). 



Living: Cerros Island, Lower California, to Cape San 

 Lucas, Lower California ; between tides. 



Material Examined: 



'a 

 55a 



Valve 



Locality 



Collector 



Where Deposited 



- Q - a m 



Formation 



Period 



Ant.. 

 Int. . 

 Post. 

 Int.. 

 Post. 

 Ant.. 

 Int.. 

 Int.. 

 Int. . 

 Post. 

 Post. 

 Post. 

 Post. 

 Int.. 

 Int.. 

 Post. 

 Ant.. 

 Int.. 

 Post . 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Coal mine, W. side Pt. Loma, 



Cal 



Loc. 108, 2 mi. N. of Pt. 



Loma, Cal 



Loc. 108, 2 mi. N. of Pt. 



Loma. Cal 



Loc. 108, 2 mi. N. of Pt. 



Loma, Cal 



Deadman Id., San Pedro, Cal. 



Deadman Id., San Pedro, Cal. 



Deadman Id., San Pedro. Cal. 



F.C.Clark 



F.C.Clark 



F.C.Clark 



F. C. Clark 



F.C.Clark 



C. L. Hubbs 



Mrs. Kate Stephens 



F. Stephens 



C. L. Hubbs 



C. L. Hubbs 



C. L. Hubbs 



Mrs. Kate Stephens 



C. L. Hubbs 



Cal. Acad. Sci 



Cal. Acad. Sci 



Cal. Acad. Sci 



Arnold Coll 



Arnold Coll 



Arnold Coll 



F. C. Clark Coll 



F. C. Clark Coll 



F. C. Clark Coll 



Berry Coll. Cat. 3916. 



Berry Coll. Cat. 3916 . 



Berry Coll. Cat. 3922 . 



Berry Coll. Cat. 3917. 



S. Diego Soc.Nat.Hist. 



S. Diego Soc.Nat.Hist. 



S. Diego Soc.Nat.Hist. 



S. Diego Soc.Nat.Hist. 



S. Diego Soc.Nat.Hist. 



Berry Coll. Cat. 3922 . 



Cal. Acad. Sci 



Berry Coll. Cat. 3931 . 



Cal. Acad. Sci 



Dept. Geology, 



Stanford Univ 



Dept. Geology, 



Stanford Univ 



Dept. Geology, 



Stanford Univ 



[ 351 

 [ 351 

 [ 351 

 [ 344 

 [ 352 

 [ 495 

 [ 343 

 [ 941 

 I 497 

 [497c 

 [497d 

 [ 342; 

 [ 496 

 [ 518; 

 [ 518; 

 t 518 

 [ 685 

 [ 686 

 [ 687 



Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 

 Upper 



San Pedro . 

 San Pedro . 

 San Pedro . 

 San Pedro . 

 San Pedro . 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 

 San Pedro. 



t 



1 



? 



Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 ? Pleistocene 

 ? Pleistocene 

 ? Pleistocene 



Remarks: So far as the shell characters go this species is 

 extremely close to /. conspicmts, differing principally in its 

 strong, coarse sculpturing. It naturally follows that poor or 

 badly eroded specimens are exceedingly difficult to separate 

 when the two species occur together. The best preserved of the 

 fossil specimens display considerable variation even within the 

 specific limits, those from Point Loma being much flatter and 

 showing a distinctly sparser, cruder sculpturing than those 

 collected at Santa Monica by Dr. Clark, but the material is not 

 sufficient to justify one in recognizing separate races for the 



