IPMG MID) QC Ils 
AVICULOPECTEN AEKENIS) pesianislemio cele sma (snee sete an atte ee ae et eee ee te 
Fig. 1. Left valve of an average size specimen. 
la. Right valve of a smaller shell, in which the sinus is deeper beneath the anterior ear. 
AVICULOPECTEN “EUREKENSIS: «sso eae o22 =< see a oac oe eee saisce se ce asin ae oe ee eee 
Fig. 2. View of a left valve compressed laterally. 
3. Left valve with the anterior ear restored in outline. Shell flattened by compression. 
AVICULOPECTEN, HAGUED 22 ison - clos seec en ecine Suits caysneenieins ase eee een a eee eee Poe 
Fig. 4. Left valve with the outline of the posterior basal margin restored from the matrix, 
the margin of the shell having been broken away. 
MYALINA \NEMBESIS=. soo. an speisssoasiecni tense ac. saci onis aaa e Soe e Sees ee eae ee eee eee 
Fig. 5. Left valve with the beak broken away. See plate xxii, fig. 7. 
MYALINA CONGENERIS . S Gano Sosa COU SSO One DSN. Goan aaaose Sete poo coosibe assscche 
Fig. 6. View of the snares? left caine collected. It is about inreafourths of ahs size of 
the largest specimen. See plate xxii, fig. 10. 
STREBLOPTERIA |GIMILIS'53-.!hscs seicsc ee ee oa as os eee ooo eae oe enon en se ee So eee 
Fig. 7. Right valve. See plate viii, figs. 4, age 
MODIOLA.?. NEVADENSIB 2 <vic\-- oc «cece co seen cones ce soeien aces ateonvences dececmuccleorese cee 
Fig. 8. View of a somewhat compressed specimen of the right valve. 
SANGUINOLITES'? (NAINTA 322% 232 3-25 a2 sos e ee alee es comes Sore oe eee ee eee ee ee eee 
Fig. 9. Right valve. 
PTERINEA "PINTOENSIS cos asics Vos oo siasdece sce cisaces dene ciecse osceiac eae ctecarieaecieaecieeneaa eae 
Fig. 10. View of left valve, enlarged to two diameters. 
PINNAVINEXPEOTANS moa cmeecisscessecisesenceensiceneseaeesnesesseae oe ene e ence ce tannes once cece 
Fig. 11. View of posterior half of left valve. 
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