Vol. XI] BERRY— FOSSIL CHITONS 



Material Examined : 



447 



Valve 



LOCAMTT 



Collector 



Where Deposited 



2££ 

 MS 



Formation 



Period 



21 

 1 



T2 

 T12 



?2 



n 



Tl 

 3 

 4 

 1 



1 



Int. 



Post. 



Ant. 



Int. 



Post 



Ant, 



Post 



Ant. 



lut 



Int. 



Int. 



Nob Hill Cut, San Pedro, Cal. 

 Nob Hill Cut, San Pedro, Cal. 

 Deadman Id., San Pedro, Cal. 

 Deadman Id., San Pedro, Cal. 

 Deadman Id., San Pedro, Cal. 

 ?Deadman Id., San Pedro.Cal 

 ?DeadmanId.,San Pedro.Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Long Wharf Canyon, Santa 



Monica, Cal 



Los Cerritos Hill, Long Beach, 



Cal 



OldroydColl. 

 OldroydColl. 

 Arnold Coll... 

 Arnold Coll... 

 Arnold Coll.. 

 OldroydColl. 

 OldroydColl. 



F.C.Clark.. 

 F. C. Clark. . 

 F.C.Clark.. 

 T. S. Oldroyd 



(Dcpt. Geology, 

 { Stanford Univ . . . 

 IBerry Coll. Cat. 3971 

 Dept. Geology, 



Stanford Univ .... 

 Dept. Geology, 



Stanford Univ .... 

 Dept. Geology, 



Stanford Univ .... 

 Dept Geology, 



Stanford Univ .... 

 Dept. Geology, 



Stanford Univ. . . . 

 Dept. Geology, 



Stanford Univ .... 



F. C. Clark Coll 



F. C. Clark Coll 



Berry Coll. Cat. 3966 



Dept. Geology, 

 Stanford Univ .... 



I 657| 



[ 658] 

 [ 693] 

 [ 695] 

 t 696] 

 [673] 

 [ 674] 

 [ 760] 

 [ 761] 

 I 762] 



Lower San Pedro. . . 



Lower San Pedro. . . 



T 



T 



? 

 ?"Upper San Pedro' 

 ?"Upper San Pedro" 

 Upper San Pedro 

 Upper San Pedro 

 Upper San Pedro 



665] Upper San Pedro. 



Pleistocene 



Pleistocene 



? Pleistocene 



T Pleistocene 



? Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



Remarks: Specimens of a nearly smooth Mopalia, believed 

 for the most part to be identical with the recent M. acuta (Car- 

 penter), have been seen from several horizons, but the material 

 is frequently so poor that one cannot be absolutely certain of 

 the identification, especially since the recent forms themselves 

 belonging to this group are still very insufficiently known. 

 Most of the specimens are very small, and this, with the yel- 

 low-brown maculation still visible now and then, gives support 

 to the view that they are not forms of lignosa. On the other hand 

 only one or two of the valves possess even a trace of the delicate 

 sutural denticulation supposedly characteristic of acuta, the 

 sutural margin in most instances being smooth. The largest 

 of the specimens listed [695] is but 15.8 mm. in diameter. The 

 largest of the Long Wharf Canyon specimens [762], which is 

 believed to be more surely identified, has a diameter of only 9.2 

 mm. The largest of those from the Nob Hill Cut [657] is 

 12.3+ mm. in diameter. These two lots at least, as well as the 

 specimen from Los Cerritos Hill, appear to represent the same 

 species, but it may be that some of the Deadman Island speci- 

 mens are really young lignosa. 



