62 Brady and Crosskey — Notes on Fossil Ostracoda. 



Lewiston, 110 feet above the sea. Only two species of Mollusca 

 can we find yet determined from near this place, viz. : Mtja aren- 

 aria and Leda truncata, both also Scotch fossils. The associated 

 Ostracoda are : 



Cythere emarginata (Sars). 

 Cytheridea Sorbyana (Jones). 

 Gytheropteron inflatum (B., C, and E., MS.). 

 Sclerochilus contortus (Norman). 



Montreal. — Upon examining catalogues given by Dr. Dawson in 

 the Canadian Naturalist, it appears that out of 20 species of Lamelli- 

 hrancMata, 15 occur fossil in Scotland, and 17 out of 27 species of 

 Gasteropoda. The beds contain nearly all the most characteristic 

 Scotch glacial fossils. The associated Ostracoda are : 



Cytheridea Sorbyana (Jones). 

 Cytherura Robertsotii (Brady). 

 Gytheropteron complanatum, nov. sp, 



inflatum (B., C, and R., MS.). 

 ,, angulatum (B.,C., and E., M S.) 



Eucythere argiis. 



Cythere MacChesneyi, nov. sp. 



„ Dawsoni (Brady). 



„ globulifera (Brady). 



,, Logani, nov. sp. 

 Cytheridea papilloma (Bosquet). 



,, punctillata (Brady). 



There is no doubt both that many more species of Ostracoda will 

 be discovered upon examination of larger quantities of material than 

 we have yet obtained, and that the number of Mollusca will be 

 increased by every fresh exposure of the clays ; but these lists have 

 been given, merely tentatively to indicate general relationships, 

 which, when further developed, may prove of geological value in 

 classifying the various deposits of the Glacial epoch. 



One of the writers of this paper (Mr. Brady) has described 29 

 species of recent Ostracoda from the Gulf of St. Lawrence, dredged 

 in depths varying from 10 to 60 fathoms, but in one case 250 

 fathoms (Annals and Mag. Nat. Hist., Dec, 1870). Of these 29 

 species, 13 are found in our list of fossils from the American glacial 

 clays, viz. : 



Cytheridea papillosa. 



„ punctillata. 

 Eucythere argus-. 



Cythere leioderma. 

 „ lutea. 

 „ emarginata, 

 „ concinna. 

 , , dunelmensis. 

 ,, Dawsoni. 



Xestoleberis depressa. 

 Cytherura undata 

 Gytheropteron nodosum. 



Although, as Mr. Brady remarks, it is unwise to generalize hastily, 

 yet we cannot help noticing that the general facies of the recent 

 Ostracoda from the Gulf of St. Lawrence much more nearly ap- 

 proaches to that of the Shetland seas or of the Scottish glacial clays, 

 than it does to that of England, while it has scarcely anything in 

 common with that of the Mediterranean, — a fact which has an im- 

 portant connexion with the suggestions we have made in this paper. 



LIST OF SPECIES. 



I Cythere leioderma (Norman), Saco, Maine. 

 X „ lutea (MiJller), Saco, Maine. 



,, MacChesneyi, nov. sp., Saco ; Saxicava Sand, Montreal ; Dr. D. 

 X ,, emarginata (Sars), Portland, Lewiston, Saco. 



X „ concinna (Jones), Portland. Rare. 



„ Dawsoni (Brady), Montreal, Portland. Rare. 



