340 



rALjBONTOLOSY Of NEW-YORK. 



I have repeated, in this volume, figures of but two of the species already given in the 

 Report of the Fourth District. These are fig. 3, plate 83, and fig. 1 c, plate 84, which will 

 be described in connexion with the other species on the same plates. In addition to these, the 

 following species, represented in the woodcut (figs. 1, 2, 5, 6 and 7), were found near Newark 

 in Wayne county, and are described in the Report of the Fourth Geological District of New- 

 York, page 138. 



Fig. 1. CornulitCB sp. 



2. Orthoctras laeve. 



3. Loxonema boydii, te« also fig. 3, pi. 83. 



4. Euomphalus sulcatua, " fig. 1 c, pi. 84. 



Fig. 5. Spirifer sp. 



6. Atrypa sp. 



7. Avicula triquetra. 



FOSSILS FROM THE LIMESTONE AT GALT, CANADA WEST. 



The fossils from this locality are peculiar, being nearly all of new species, and, with one or 

 two exceptions, different from those within the limits of New-York. My attention was first called 

 to the peculiar bivalve shells on Plates 80 and 81, in 1847. In 1848, I visited the locality, and 

 obtained many other species. From the nature of the limestone, which appeared to succeed the 

 well characterized limestone of Niagara falls, and from the similarity of some of the fossils 

 with those of the Onondaga-salt group of New-York, I was inclined to refer the formation to 

 the base of the latter group. A simple inspection of the Plates 79-84, will show that these 

 fossils are typical of a distinct period from that of the Niagara group ; and though the few 

 species yet known from the base of the Onondaga-salt group in New- York seem scarcely suffi- 

 cient to indicate a well marked period, or to claim positive identity in age with those of the. 

 Gait limestone, yet we^re compelled either to regard them thus, or to rank the latter as a 

 group entirely distinct from any yet recognized. The Gait fossils, as a group, are not only 

 distinct from those of the Niagara period, but equally distinct from those of the succeeding 

 geological periods of the Lower and Upper Helderberg limestones. They do in fact make a 

 nearer approach to those regarded as devonian types, than to any group of silurian age ; and 

 yet vre are able to prove their position to be quite below the limestone holding Pentamerus 



