Vol. XI] 



BERRY— FOSSIL CHI TOSS 



451 



Material Examined . 



Valve 



Locality 



Collector 



Where Deposited 



Cos 



Formation 



Period 



1 

 1 



1 

 2 

 1 

 1 



3 



1 



4 



6 



17 



?2 

 2 



1 

 1 



Ant. 

 Ant. 

 Int 



Int. 

 Post 

 Ant, 



Int. 



Ant, 



Int. 



Ant. 



Int. 



Int. 

 Post 



Post. 

 Ant. 



Int. 



Int.. 



Chiton Bed, Pt. Fermin, Ca! . 

 Chiton Bed, Pt, Fermin, Cal. 

 Chiton Bed, Pt. Fermin, Cal . 

 Chiton Bed, Pt, Fermin, Cal. 

 Chiton Bed, Pt. Fermin, Cal . 

 Chiton Bed, Pt. Fermin, Cal . 



Chiton Bed, Pt, Fermin, Cal . 



Near lighthouse, Pt. Fermin 

 Cal 



Near lighthouse, Pt. Fermin 

 Cal 



Deadman Id., San Pedro, Cal 



Deadman Id., San Pedro, Cal 



Deadman Id., San Pedro, Cal 

 Deadman Id., San Pedro, Cal 



Deadman Id., San Pedro, Cal, 

 ? Deadman Id., San Pedro, 



Cal 



? Deadman Id., San Pedro, 



Cal 



? Deadman Id., San Pedro, 

 Cal 



E. P.4E. M.Chace, 1918 

 E. P.&E. M.Chace, 1918 

 E. P. & E. M. Chace, 1918 

 E. P.&E. M.Chace, 1918 

 E. P. & E. M. Chace, 1918 

 E. P. Chace & S. S. Berry, 



1920 



E. P. Chace & S. S. Berry, 



1920 



Cal. Acd. Sci 



Berry Coll. Cat. 4077 . 

 Berry Coll. Cat. 4077 



Cal. Acd. Sci 



Berry Coll. Cat. 4077 



Chace Coll . 

 Chace Coll . 



E. P.&E. M.Chace, 1918 



E. P. & E. M. Chace, 1918 

 Arnold Coll 



Arnold Coll. 



Arnold Coll. 

 Arnold Coll. 



Arnold Coll. 



Oldroyd Col! . 

 OldroydColl. 



Berry Coll. Cat. 4108 



Berry Coll. Cat. 4108 

 Dept. Geology, 



Stanford Univ .... 

 Dept. Geology, 



Stanford Univ .... 

 Berry Coll. Cat. 5183 

 Dept. Geology, 



Stanford Univ .... 

 Berry Coll. Cat. 5183 



Dept. Geology, 

 Stanford Univ . 



Dept. Geology, 

 Stanford Univ . 



Oldroyd Coll Berry Coll. Cat. 5181 



11036] 

 [1036] 

 [1037] 

 [1037] 

 [1038] 



[1408] 



[1409] 



[1098] 



[1099] 



[ 727] 



[ 698] 

 [ 700] 



[ 699] 

 [701] 



[ 675] 

 [ 676] 

 [ 6761 



Lower San Pedro . 

 Lower San Pedro. 

 Lower San Pedro. 

 Lower San Pedro. 

 Lower San Pedro . 



Lower San Pedro. 



Lower San Pedro. 



Lower San Pedro. 



Lower San Pedro. 



? 



? 



?"Upper San Pedro" 

 ? "Upper San Pedro" 

 ?"Upper San Pedro" 



Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 

 Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



Pleistocene 



? Pleistocene 



? Pleistocene 

 ? Pleistocene 



? Pleistocene 

 ? Pleistocene 



Pleistocene 

 Pleistocene 

 Pleistocene 



Remarks: There are numerous Mopalia valves in the col- 

 lections seen which have given more than their share of trouble 

 to identify. Most of them are quite close to common forms of 

 the recent M. ciliata, and one encounters little difficulty in so 

 naming- them. But other specimens appear to have an aspect 

 of their own, especially two or three intermediate valves which 

 show a peculiar, broad, triangular, finely longitudinally striate 

 jugal area. There is also variation in several other directions 

 so that a thorough revision of the recent forms may show that 

 I have included more than one species here. For the present 

 there is little to be done but follow Pilsbry in his redefinition 

 of ciliata. He regards the common Monterey form as typical 

 for Sowerby's species. If this be so, then some at least of the 

 fossils are correctly determined. Head valves are probably the 

 hardest to satisfactorily identify, as they so often closely re- 

 semble those of M . muscosa. 



13. Mopalia cf. sinuata Carpenter, 1864 

 (Plate VI, figs. 7-8.) 

 1864. ? Mopalia sinuata Carpenter, Rep. Brit. Assoc. Adv. Sci. 

 1863, p. 648. 



