W. TJpham — Fishing Banks. 127 



18T7 Prof. C. H, Hitchcock suggested that the Fishing Banks 

 are of Tertiary age ;* and much earlier Agassiz had taught his 

 classes that they must consist superficially of drift, the eastern 

 continuation of the drift sheet of the northern United States 

 and of Canada. Both these theories were fully justified in 

 1878, when in the service of the U. S. Commission at Gloucester, 

 Mass., I gathered from the fishermen of that port many speci- 

 mens of rocks that had been brought up from the bottom of 

 the Fishing Banks by their lines becoming entangled in the 

 coralline growths attached to these rock masses. A large pro- 

 portion of the stones so drawn up are rounded and snbangular 

 fragments of granitic, gneissic, and schistose rocks, evidently 

 transported to their present position through the agency of 

 ice, either by an ice-sheet during the Glacial period, as was 

 doubtless true for a large part of this drift, or by icebergs and 

 floes, which still are contributing yearly to the drift of the 

 Grand Bank. Apparently a smaller proportion, but more 

 likely to be brought ashore by the fishermen, consists of fossil- 

 iferous sandstone arid limestone, often well filled with shells or 

 with their empty casts. Many of these fossiliferous rock frag- 

 ments, varying from one pound to a hundred pounds or more 

 in weight, were collected and submitted to Prof. A. E. Verrill 

 for determination of their species, concerning which he wrote 

 as follows in this Journal for October, 1878 (III, vol. xvi, pp. 

 323-324). 



Among the most important results of the investigations made 

 by the party connected with the IT. S. Fish Commission, stationed 

 at Gloucester, Mass., during the present season, is the discovery 

 of fragments of a hitherto unknown geological formation, appar- 

 ently of great extent, belonging probably to the Miocene or later 

 Tertiary. The evidence consists of numerous large fragments of 

 eroded, but hard, compact, calcareous sandstone and arenaceous 

 limestone, usually perforated by the burrows of Saxicava ragosa, 

 and containing in more or less abundance fossil shells, fragments of 

 lignite, and in one case a spatangoid sea-urchin. Probably 

 nearly one-half of the species are northern forms, still living on 

 the New England coast, while many others are unknown upon 

 our coasts and are apparently, for the most part, extinct. From 

 George's Bank about a dozen fossiliferous fragments have been 

 obtained, containing more than twenty-five distinct species of 

 shells. Among these one of the most abundant is a large thick 

 bivalve (Isocardia) much resembling Cyprina Islandica in form, 

 but differing in the structure of the hinge. This is not known 

 living. Mya truncata, Ensatella Americana^ and the genuine 

 Cyprina are also common, together with a large JVatica, a Cyclo- 

 cardia (or Venericardia) allied to O. borealis (Con.), but with 



* Geology of New Hampshire, vol. ii, p. 21. 



