106 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. 



PeCTEN (PaTINOPECTEN) TUUNEKI 11. »{>. 



PI. XXXIV, fig. 4: PI. XXXV, fig?, l' an.l H. 



1888.? Pirin, propahilux Coojier, Seventh Ann. Kept. Cal. fi-t. Min., 1888, p. 25S ("Tomales, Marin 

 County" ). 



Dexci'ijdlon. — Shell averaging about 70 to 80 millimeters in altitude, length 

 same as height, both valves equally compressed, equilateral, and with smooth 

 margins; base regularly rounded; sides nearly straight and sloping at a rather low- 

 angle. Right valve with eighteen to twenty -two high, narrow, tlat-topped, conea\e- 

 sided ribs, which, in most cases, show a distinct medial sulcus after reaching a 

 length of 30 or 35 millimeters; interspaces much wider than ribs, round bottomed 

 and sometimes ornamented near the end by a faint intercalary riblet; whole surface 

 of disk finely concentrically striated; hinge line slightly longer than one-half 

 length of dislv; ears equal, rectangularly truncated; anterior ear sculptured by 

 four or five prominent radiating ridges and numerous tine incremental lines; l>yssal 

 notch shallow but distinct; posterior ear with sculpture similar to anterior. Left 

 valve with narrow rounded ribs, which are separated by round-bottomed and 

 concave-sided interspaces much wider than the ri))s; surface sculptured by fine, 

 distinct, wavy, concentric lines; ears as in right valve, except lacking byssal notch. 

 Hinge as in P. enurinuf!. 



Dlmendons.^Ah. 65 mm.; long. 65 mm.; hinge line 35 mm.; diameter 6 mm. 



The type is a smaller specimen than the average of this species. 



P. ttmieri is allied to the group of which /■'. caurinim is the commonest 

 representative. Its diagnostic characteristics are its small size for one of this 

 group, narrow, sulcated ribs on right valve and radially striate ears. 



Found in the Pliocene at Arroyo San Antonio, near Tomales Bay, Marin 

 County, by Dr. H. W. Turner, late of the United States Geological Survey, 

 after whom it is named. 



The type, which is figured, is now in the collection of the department of 

 geology, Leland Stanford Junior University. 



Pliocene. Tomales Bay, Marin County (Turner). 



Pecten (Nodipecten) veatchii Gabb. 



PI. XL, figs. 1 and la. 



1869. Peeten Veatchii Gabb, Pal. Cal., vol. 2, 1869, p. 32, pi. 10, fig. 56. 



1888. Liropeclen reatchii Gabb, Coojier, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246. 



1898. Pecten Veatchii Gabb, Dall, Trans. Wagner Free Inst. Sci., vol. S, pt. 4, 1898, p. 705. 



Pescription. — Shell averaging about 130 millimeters in altitude, slightly broader 

 than high, subequivalve, eqiiilateral, of medium thickness, somewhat ventricose, 

 and with margins finely serrate; base regularly rounded; sides sloping abo\-e with 

 slight concavity. Right valve slightly less ventricose than left, with about 8 

 broad, flat ribs arranged in pairs, and a few small linear ribs on the sides; the 



