Figure 1. 



Figure la. 

 Figure 2. 



Figure 3. 



Figure 3a. 

 Figure i. 



Figure 5. 

 Figure 5a. 



Figure 6. 



Figure 7. 



Figure 8. 



Figure 9. 



Figure 9a. 

 Figure 10. 



PLATE XXXVII. 



Chonetes Manitobensis (page 281). 



Specimen from the north side of Manitobca Island shewing the e.xterior 

 of the ventral valve and tlie spines on its cardinal border. 

 Twice the natural size. 



Portion of the same enlarged four times, to sliew the surface markings 

 more clearly. 



Another specimen from Manitoba Island, shewing the whole of the 

 dorsal valve, and the hinge area, but not the cardinal spines, 

 of the ventral valve. Twice the natural size. 



Oethis (Schizophoria) Manitobensis (page 283). 



Specimen from a small island in Dawson Bay, shewing the exterior of 

 tlie " dorsal " or most convex and brachial valve only.* 



Portion of tlie same, twice tlie natural size. 



Specimen from the same locality, shewing the front margin and relative 

 convexity of both valves. 



Cast of the interior of the " dorsal " or bracliial valve of a shell which 

 is probably referable to this species, from Devils Point, Lake 

 Winnipegosis. 



Unibonal region of the same, enlarged three times, to shew the impres- 

 sions made by the very slrort median septum in the beak and 

 by the two divergent brachial processes. 



Steophodonta interstrialis (page 286). 



Specimen from a small island on the east side of Dawson Bay, shewing 

 the exterioi' of tlie ventral valve. 



Spirifera (Martinia) Richardsonii (page 287). 



Specimen from the south-west shore of Dawson Bay, which is probably 

 referable to this species, sliewing the interior of the shell, the 

 spiral coils and hinge dentition. 



Atkypa reticularis (page 289). 



Specimen from Pentamerus Point, Lake Manitoba, in which most of tlie 

 broad marginal fringe or foliated expansion of tlie ventral 

 valve is preserved. 



Terebratula Sullivanti (page 291). 



Dorsal view of a specimen from Whiteaves • Point, Dawson Bay, with 

 a short mesial sinus in each valve and the anterior border 

 emarginated. 



Ventral view of the same. 



Dorsal view of another specimen from a small island in Dawson Bay, 

 north of Salt Point, in which there is no sinus in eitlier valve, 

 nor any emargination of the anterior border. 



^''Fhlert, in Fischer's >tanuel de Conchyliologie, \). 1287, calls the corresponding 

 valve of Orthis {'Schizophoria) striatuia, the "ventral." 



