108 Sotitas— On the Origin of Freshwater Faunas. 
PoLyzoa. | A. edentula (Pall.) 
Laguncula repens (Farr. ) e ai aa : 
Bowerbankia densa (Farr. ) ie aren d Per. 
7 eee nadonta ponderosa (Pfr. ) 
pachone | Dreissena polymorpha (Ben.) 
LAMELLIBRANCHIATA, | D. caspia ens, 
D. rostriformis (Desh.) 
Corbicula fluminalis (Mill. ) D. brardii, Brgn. var. caspia (Grm.) 
Cardium edule (Linn. ) 
C. edule, var. rusticum GASTROPODA. 
C. caspium (Eich.) 4 Ose . 
Geranena (Eich.) Neritina littorata (Eich. ) 
C. trigonoides (Pall.) N. schulzii (Grm.) 
C. trigonoides, var. crassum (Grm.) Hydrobia caspla (Eich. ) 
C. pyramidatum (Grm.) H. dimidiata (Eich.) 
G@ then _ (Grm.) | H. spica ; ( Eich.) 
C. longipes (Grm.) | H. stagnalis (Linn. ) 
C. barbot-de-marnii (Grm.) Eulima yar ; ( Eich. ) i 
Go eatillus (Hich.) | Bithynia eichwaldi (Krynicki.) 
C. pseudocatillus (Abich.)? Lithoglyphus ? caspius (Krynicki.) 
AGlaenaekeenriae cals: (Eich.) Planorbis micromphalus (Fuchs.) ? 
Separating the Mollusca, we have the following list of genera, in which I have 
added the name of the group of beds in which each genus is first known to occur: 
Corbicula, Lisp. Lower Eocene. 
Cardium, 12 sp., Upper Jura. 
Adacna, 4 sp., Lower Pliocene. 
Anodonta, isp: Devonian. 
Dreissena, 5 sp., Upper Eocene. 
Neritina, 2 sp. Lias. 
Hydrobia, 4 sp., Middle Jura. 
Eulimus, MSDs, Trias. 
Bithynia, i-sp,, Middle Jura. 
Lithoglypha, 1 sp., Lower Pliocene. 
Planorbis, 1 sp., Lias. 
It is generally admitted that this Molluscan fauna has its closest affinities with 
that of the ‘‘ Congerien” strata of Upper Pliocene age, and I therefore add a list of 
the latter for comparison. 
* Fossils of ‘‘Congerien”’ Strata. Sandberger, p. 676, etc. 
