19 



10 Nucula Rugulosa, p. 171 



Convexa, p. 172 



Pisum, p. 172 



Exigua, p. 172 



Patagonica, p. 167 



Thracseforniis, p. 



11 

 12 

 13 

 14 

 15 



16 

 17 



18 



169 



Delphinodonta, app. 

 Tenuisulcata, app. 

 Pygmaea, app. 



19 Unio Siculus, app. 



20 

 21 

 22 

 23 



24 

 25 

 26 

 27 

 28 

 29 

 30 

 31 

 32 

 33 

 34 

 35 

 36 

 37 

 38 

 39 



- Perdix, p. 188 



- Hopetonensis, p. 198 



- Cariosus, p. 1 90 



- Circulus, p. 201 



- Obliquus, p. 186 



- Irroratus, p. 181 



- Undulatus, p. 175 



- Tuberculatus, p. 182 



- Intermedins, app. 



- Coelatus, p. 175 



- Cornutus, p. 179 



- Cylindricus, p. 182 



- Pliciferus, p. 176 



- Semigranosus, app. 



- Subtentus, p. 176 



- Multistriatus, p. 176 



- Tampicoensis, p. 188 



- Gracilis, p. 174 



- Lachrymosus, p. 177 



- Compressus, p. 174 



40 Unio 



41 



42 



43 



44 



45 



"46 



47 



48 



49 



50 



51 



52 



53 



54 



55 



56 



57 



58 



59 



60 



Fragosus, p. 178 



- Brevidens, p. 198 



- Tenuissimus, p. 206 



- Ovatus, p. 184 



- Delphinus, app. 



- Pyramidatus, p. 186 



- Crassidens, p. 184 



- Ebenus, p. 202 



- Ochraceus, p. 190 



- Cseruleus, p. 194 



- Phaseolus, p. 207 



- Securis, p. 184 



- Clavus, p. 187 



- Marginalis, p. 206 



- Gibbosus, p. 207 



- Splendidus, p. 190 



- Egyptiacus, p. 198 



- Collinus, app. 



- Subrotundus, p. 203 



- Ravenelianus, p. 187 



- Lanceolatus, p. 204 



PLATE XXI. 



1 Unio Cooperianus, p. 180 



2 - 



3 - 



4 - 



5 - 



6 - 



7 - 



Orbiculatus, p. 192 

 Paranensis, p. 202 

 Lens, p. 201 

 Capsseformis, p. 191 

 Trigonus, p. 185 

 Ellipsis, p. 188 



