PLATE 17. 



Page 

 lli.. 1. PUOTOCAHDIA KARA 17(1 



1 , (i. A right-side \ iew of au adult specimen, natural size. 



1, ft. A posterior view of au internal cast, magnified. 



I,c. A left-side view of same, showing the muscular impressions and the doubly-waved or 

 sinuous character of tin' pallia] line. 



I'll. '.'. Lt'i IN \ sniCVDATA 133 



'->, a. A rather small snbquadrangular specimen, right side. 



■2,6. Dorsal view of same. 



2,c. A smaller individual, left-side view, with anterior dorsal sulcus wanting. 



2, d. Dorsal view of same. 



2,e. A large, somewhat differently-formed, specimen, with the anterior dorsal sulcus well de- 

 fined, left side. 

 •i.f. A large specimen, right side, with the anterior dorsal sulcus broad and shallow. 



FlG. 3. LUCINA SUBUNDATA, rur. VENTRICOSA. 135 



:<,(<■ A right-side view of the type-specimen of this variety, with lower margin broken away. 



3, 6. Dorsal view of same. 



3,1, {bis.) A left side of a larger internal cast, showing muscular and pallia! impressions. 

 [This figure is directly under fig. 3, a.] 



FlG. I. LUCINA OCCIDENTALIS 134 



I. a. A dorsal view of an adult specimen. 



t, 6. A right-side view of same. 



4,c. Same view of au internal cast, showing muscular and pallia] impressions. 



4,(7. V fragment of a right valve, showing cardinal teeth. 

 1'k,. 5. VeOTella subtcmida 154 



.">,«. Dorsal side of an internal cast (type-specimen). 



."'. 6. Right side of same, showing muscular and pallia] impressions. 

 ]"[<;. li. Crassateixa Evansi 117 



ti, ». Right side of a perfect specimen. 



6, b. Anterior side of same. 



6, c. Dorsal view of same. 



ti.rf. Left side of an internal cast, showing muscular and pallia] impressions, as Well as the 

 finely crenate character of the free margins. 



Fig. 7. Nucula subpjlana 9U 



7,«. Left side of the type-specimen, consisting of an internal cast, showing muscular and pal- 

 lial impressions. 



7, 6. Dorsal view of same, showing impressions of the hinge-denticles. 



Fig. 8. Thetis circularis 190 



~.<i. Left side of the type-specimen, which is a medium-sized, perfect example. 



8,6. Right side of a larger internal cast, showing the pointed, vertically-ascending pallia! 



sinus. 



8, c. An anterior view of the same. ( See also wood-cuts in text.) 



I'll., t). EltlPIlVI.V GREGAlilA 1-1 



9,n. Right side of the perfect type-specimen, magnified two diameters. 

 ',*, 6. Dorsal view of same. (See also wood-cuts in test.) 

 Figs. 10 and 12. Callista pellucida 187 



10,«. Right side of the partly-exfoliated oval type-specimen. 



10,6. Left side of an internal cast, showing muscular and pallia! impressions. 



10, c, Right side of a i e rounded specimen. 



I0,rf. Au outline dorsal view of specinicu represented by li.c. 10,6. 



