PLATE XXV. 



mi()Cp:ne pectens. 



[Unless otherwise statetj jill figures are apiirnxiniately natural size.] 



Page. 



Fig. 1. Pediii (Liirnjn'ctcn) iiiiignuliii (.'immii. V. 8. X. M. 133L'.'). Cotype 77 



Exterior (if valvf, sliowing characti'ristic sculpture ami shape of rib.f; altitude of fragment 

 130 mm. Vaqueros fiirination (lower Miocene), Santa Inez Mountain?, Santa Barbara 

 County, Cal. (M. B. ) 

 Fii:. 2. I'cctcn (I'litjiKideniiim) ivrrdsensin (iabli vur. iiiciidniliull! ii. var. U. S. N. M. 1I.)-1S4'.I. 



Type S4 



Exterior of right valve; altitude 43 mm. Mioeene, Santa Koadia, Lower California. 

 (M. B.) 



Fig. 2a. Same specimen at* tig. 2 84 



Exterior of left valve. ( M. B. ) 



Fig. 21). Same specimen as fig. 2 .H4 



Profile of both valves, viewed innn the rear. (M. P. ) 



Fig. 3. Peclcii ( Pliu/iorteniiim ) eldridr/ci n. sp. U. 8. N. M. 164S.")0. Tyjx' 87 



Exterior of left valve; altitude 20 mm. San Pablo formation (ujijier .Miocene), McKit- 

 trick district, Kern County, Cal. (M. P.) 



Fig. '.ill. Same specimen as fig. 3 S7 



View of interior of left valve. (M. P.) 



Fig. 3/). Same specimen as fig. 3 87 



Profile of left valve, viewed from rear, showing great convexity. (M. P. ) 



Fig. 4. Pecteii (Plagiodetiimn ) eklridr/ei n. sp. U. S. N. M. 164S50. Cotype 87 



Exterior of right valve (anterior ear slightly broken); altitude 17 mm. Same locality as 

 tig. 3. (M. P.) 



Fig. 4ft. Same .specimen as lig. 4 87 



Profile of right valve as viewed from the rear. ( JI. P. ) 



Fig. 5. Pcc/Cji {Plitifioctfniiiin) fidridr/ci n. s|). 1'. S. N. M. IfU.'^oO. Cotype 87 



Exterior of right valve (anterior ear broken); altitude 23 mm. Same locality as fig. 3. 

 (M. P.) 



Fig. ria. Same sjiecimen as lig. 5 87 



Profile of right valve as viewed from the rear. ( M. P. ) 



Fig. II. I'fdcn (Pl'ujiocieuiviii ) ddridgri n. sp. I'. S. N. M. ](i4850 87 



Exterior of fragment of a large valve of this species. Same locality as fig. 3. (.M. P.) 



194 



