I'l.ATli 111— Lonllnucl. 



ELKANIA, FoKi). 



Page 75. 

 Elkania desiderata, Billings (sp.). 



Fig. 15. The interi<ir of a. pedicle-valve ; showing- the deep central iinpi-es'si<in (pedicle-pit cif Fdku), snb- 



cardinal, crescentic and external scars, the divei'ging vascular (genital ?) furrows and the liroad, 



deep lateral depressions, prohalily not of nniscular origin. X ii- 

 Fig. It). The counterpart of the same, similarly enlai-ged. 

 Pig. 17. The interior of the bi'achial valve, with the impressions of the central aiid latei-al muscles and 



crescent. X 3. 

 Fig. 18. The counterp.art of the same ; showing the muscular callosity or incipient platform. X •!■ 

 Fig. 19. An enlargement of the surface of one of the intermediate corneous layei's of the .shell ; showing 



its irregularly granulose surface. X 6. 

 Quebec gi'oup. Pointe Livix. 

 The above figures are made from Mr. E. Billinus' original specimens of the species. 



DISCINOPSIS, geii. uov. (Matthew). 



Page 105. 



DiSCINOPSIS GULIELMI, MuttlieW. 



Fig. 20. The exterior of a pedicle- valve ? ; showing the radiating ami concentric lines, ami a Haltened apex 

 which may indicate the position of the foramen. X f>. 



Fig. 21. The interior of the pedicle-valve, with the linguiform median extension .sharply detincd. and show- 

 ing the possible position of the foramen. X •'). 



Fig. 22. The connteriiart of the same. X S. 



Figs. 23, 24. Other interiors of the pedicle-valve, less satisfactorily pi-eserved. X 5. 

 All are from the St. John group. Portland, JS'ew Byunxioick. 



ACROTFIELE, Linnarsson. 



Page 9S. 



AcROTHELE Matthewi. Hiirtt (~p.), var. prijia, Mutliiew. 

 Fig. 25. The exterior of the pedicle-valve ; showing the chai-acter of the sui'face ornamentation. X •'!• 



AcROTiiELE Matthewi, Hiutt, v:ir. lata, Matlhcw. 



Fig. 26. The interior of the pedicle-valve ; showing the position of the foramen and the foramina! pits. X 3. 

 Fig. 27. An internal cast of the same valve. X 3. 

 Pig. 28. Pi-ofile of the latter. X 3. 



St. John group. Hcmford Brook, New Brunswick. 



ACROTHELE Matthewi, Hiirtt (.>!).). 



Fig. 29. The interior of a bra<-hial valve ; showing the median septum and adjacent muscular scai-s. X 3. 

 St. John group. Portland, New Brunswick. 

 Figs. 25 to 29 are from the original specimens figured by Mr. Matthew. 



ACEOTHELE SUBSIDUA, White, 



Pig. 30. 'I"he interior of the jiedicle-valve ; showing the foramen and foramina! jiits. X 2. 

 Fig. 31. The interior of the brachial valve with a faint meilian septum. X 2. 

 Middle Cambrian. Antelope Springs, Utah. 



