F* JL A. T E 2 . 



Page. 



Fig. 1. Trigonarca Salinaensis 92 



1, n. A side view of an internal cast, natural size (type-specimen). 



1, 5. The same magnified to show hiuge-teetb, muscular impressions, etc. 



I, c. An outline profile view, to show the convexity of the shell. 



Fig. 2. Yoldia microdokta 109 



An internal east, magnified two diameters, to show the minute hinge-erenulations (type- 

 Bpecimen). 



Fig. :!. Cii ^ssateixis k. obloxga 120 



'■',, a. Side view of an internal east, natural size. 

 3, 6. Dorsal view of same. 



3, c. Side view of cast of exterior, natural size (type-Specimen). 



3, il. A magnified view of right valve, showing hinge, muscular, and pallia 1 impressions. [The 

 furrow along the middle of the oblique posterior cardinal tooth is too distinctly and 

 sharply defined iu the lithograph.] 



3, e. Magnified view of" hinge, muscular, and pallia! impressions of left valve. [The small. 



compressed, posterior cardinal tooth is represented too short, and not straight aud 

 oblique enough.] 



FlG. 1. ARCOPAGELLA MACTROIDKS 202 



4, a. An internal cast of left valve (natural size), showing muscular and pallial impressions 



of type-specimen. 



4, ''. An outline figure, showing hinge, muscular, and pallial impressions of the left valve. 

 ■1, c. Same view of right valve. 



Fig. 5. Coubicula ? n re wis 103 



5, a. Cast of the interior of the right valve of type-specimen, showing muscular and pallial 



impressions and imprints of the lateral "hinge-teeth. 



5, b. An outline profile view, natural size, to show convexity. 



6, c. A magnified view of the specimen represented by lig. . r >, a. 



Fig. 6. Cokbicula ? subtrigonajjs id 



A cast of the interior "l a left valve (type-specimen), showing muscular and pallial 

 impressions, and an imperfect impression id' the hinge, apparently as eroded before 

 being imbedded in the arenaceous material now forming the enveloping rock. 



Fig. 7. Mi.s.u.i \ .' KansaSEXsis 333 



T. n. Dorsal view of an artificial Bast made in a natural mould of the shell, natural size (type- 

 Bpeciuicn ). 



7, b. A side view of a east of a larger specimen, showing the outline of the outer lip, with its 



sinuous margin. [The sinus is not deep enough in the lithograph.] 

 Fig. 8. Ostrea (undt. species) • 12 



8, <i. An internal cast of the under valve. 



8, b. Au outside view of the flat upper valve 



Fig. 9. Margarita Mudgeana 300 



'.i, <i. Cast of the interior of type-specimen. 



'.I, b. An aperture view. drawn from a gutta-percha cast made in a natural mould, of tl xte- 



rior of same. 



Fig. in. Barbatia paraixei.a '. 80 



A cast of the interior of a right .valve (type-specimen.) 

 Fig. 11. Tki.i.ina subscitula 195 



II, a. An infernal east of left valve of type-specimen (natural size), showing muscular and 



pallial impressions. 

 11. A- Same, magnified about two diameters. 



