PALEONTOLOGY. 

 PLATE V. 



Page. 

 TllAPEZHM lIKIXEI-OUItCHEXSlh 364 



I'Ki. 1. \'i»'\v of tin- left si<k* of a Npi-ciiiU'ii enlarged, showing the usual fonu. 



I'm. 'J. Oiitliiii- ciinliiial vii-w of the saiiic, sliglitly restored at the anterior extremity. 



Fig. :!. Vit-w of a right valve, iniiicrfcct, of a broader form, and showing the cast of tlio 



anterior niuseiihir imprint. 

 I-'iti. 4. View of the left si<le of a broad form, showing the outline entire, but imperfect over 



the body of the .shell. 



Tkai'K/ii'm .sfin:yiALi.s 365 



Ik;. ."). View of a largo left valve, natural size. 



I'ui. (■>. A right valve of slightly different form. 



l-'i(i. 7. Kiilarg<-inent of a similar right valve, but more constricted on the basal margin. 



Fig. t*. Outline cardinal view, restored from the last specimen. 



MYTII.US WIIITEI 360 



Vio. I). View of a left valve of the ordinary size. 

 Fk;. 10. Profile view of the same, looking ni)()n the buccal side. 

 Flii. 11. \'n'\v of a right valve, which is slightly more arcuate than Fig. 9. 

 Fig. IvJ. View of another left valve, which is even straighter than Fig. 9, and has a less 

 oblique hinge. 



V<)L.si:lla I'EitTKNUis 362 



Fig. 13. View of a left valve, natural size. 



Fic. 14. Prolile view, constructed from separated valves. 



VOLSELI-A (Modiola) iok.mosa 361 



Fi(i. 1.'). View of a left valve of small size. 



Gkammatodox ixounatus 35'J 



Fic. Hi. \'iew of a right valve, natural size, showing the prevailing form and size, al.so 



showing radiating stria-. 

 l"i(i. 17. An enlarged view of a cast of a left valve, showing the liinge features as seen on 



the cast. 

 Fu;. If^. Outline cardinal view as cousti'ueted from separated valves. 



Pi.e«'ijo.mya newtoxi 367 



Fig. 19. View of a left valve of the prevailing form. 

 Fig. 20. View of a larger right valve. 



Uosixia JUiiASSiCA •. 373 



Figs. 21, 2J. Views of left valves of the usual form and size. 



Fig. 23. Cardinal view of the specimen Fig. 22. 



Fig. 24. View of the cast of a right valve, showing the paUial liue and sinus. 



Saxicava .iurassica ■ 376 



Fig. 25. \'iew of an internal cast, natural size. 



Fig. 2;!. View, enlarged, of the left side of a specimen retaining a portion of the shell, and 



showing the pallial sinus on the cast. 

 Fk;. 27. I'.ularged cardinal view of the spccim(^. Fig. 25, showing the angularity of the 



uniboual ridge. 

 Figs. 28, 29. Enlarged cardinal and right views of a large individual, retaining a large 



l)art of the shell. 

 Fig. 30. View of one of the casts of the burrows as separated from the sun-ounding clayey 



matrix. 



P.SAMMOiti A ? prematura 374 



Fu;. 31. View of the specimen described, which is an internal cast, showing the muscular 

 imprints and pallial liue. 



A.STARTE (T) kragilis 363 



FiG.s 32, 33. Right and cardinal views, enlarged, of a specimen which we have supposed to 

 belong to this species. 



TllRACIA T 8UBLEVIS 375 



Fig. 34. View of a right valve referred to this species, by error on plate, made Fig. 24. 



Ne^ra lo.ngirostua 376 



Fig. 35. View of a left valve enlarged, showing the characters of the species. 





