23 
26 
27 
PLATE XXII. 
Unio Blandingianus, p. 200 

Burroughianus, p. 197 

Parvus, p. 196 
— Bialatus, p. 214 
Purpuratus, p. 208 


Membranaceus, p. 202 

Cuprinus, p. 208 
—— Contradens, p. 209 
Lugubris, p. 206 
—— Carbonarius, p. 184 


Lecontianus, p. 188 
— Discus, p. 197 

Parchappi, p. 212 

Guayaranus, p. 213 

Corrientesinensis, p. 
212 
Patagonicus, p. 208 


Paraguayanus, p. 212 
— Minuanus, p. 213 
Fossiculiferus, p. 213 
— Rhombeus, p. 208 
Decisus, p. 187 
Sulcatus, p. 188 
— Calceola, p, 212 
Occidens, p. 189 
Angustatus, p. 204 
Lanceolatus, p, 204 
Patulus, p. 187 







21 

28 
29 
30 
33 
50 

Unio Heros, p. 175 

Trapezoides, p. 176 
Castaneus, p. 188 
Congarveus, p. 200 

—— Olivarius, p. 195 
Glans, p. 196 
—— Obesus, p. 198 
Acutissimus, p. 177 



Pustulatus, p. 178 
Asper, p. 179 
—— Stapes, p. 179 


Perplexus, p. 181 

Arceformis, p. 182 

Donaciformis, p. 183 
—— Ziczac, p. 183 
Subovatus, p. 184 
Holstonianus, p. 213 
Fabula, p. 213 
Aretior, p. 208 
Jejunus, p. 199 





—— Vaughanianus, p. 208 
—— Arcula, p. 210 
Deltoideus, p. 211 
Lecontianus (copied 
from Lea), p. 188 
Fisherianus, p. 206 



—— Jayensis, p. 206 

Coccineus, p. 203 
Folliculatus, p. 204 
—— Vanuxemensis, p. 193 

—— Zieglerianus, p. 193 
