Geology, 4^c. of the Connecticut. 77 



At Sunderland these impressions occur in bituminous 

 shale, which often contains a little mica, and generally a 

 quantity of iron pyrites, disseminated through the rock. 

 They occur at Witmore's ferry in the north part of Sunder- 

 land, in the bank of the river. They are found most abun- 

 dant at the lowest water mark, at which time two men, in 

 less than half a day, dug out for me nearly fifty specimens. 

 Sometimes a layer of semi-crystalline dark colored carbo- 

 nate of lime, less than one twentieth of an inch thick, lies 

 between the layers of slate. The substance of the fish is 

 usually converted into coal, the thickness of which is rarely 

 more than one tenth of an inch in any part, and the color ia 

 black. In some instances, however, the carbonate of lime 

 above mentioned covers the fish, and has taken the place of 

 the matter of the fins and scales and their original light 

 grey color is preserved so perfectly as to resemble a fish 

 just taken out of the water. Some of the specimens 

 appear contorted; in others the form of the fish is whol- 

 ly lost, the fins and scales and bones, being scattered 

 about promiscuously, as if the fish had perished in violent 

 struggles, or the rock had been disturbed after its imprison- 

 ment. Yet, in the same specimen that contains one thus 

 mutilated, another will appear not more than a foot distant 

 which is whole. I have found four or five specimens in 

 which the fishes (both of them distinct,) lie across each oth- 

 er; sometimes a very thin layer of shale, and sometimes 

 none, separating them. I have another specimen, three feet 

 long and fifteen inches wide, containing seven distinct impres- 

 sions. The shale in which these ichthyolites occur,when rub- 

 bed or held in a flame, exhales a strong bituminous odour.* 



Among the impressions hitherto obtained, I can easily 

 discover three distinct species that have scales.* Two of 

 these are represented on the accompanying plate ; but the 

 third was so much mutilated, that I did not attempt to de- 

 lineate it. For at the best it is no easy matter to represent 

 them so exactly as to be of use. They are usually a little in- 

 distinct on their border,and not unfrequently injured bypyrites. 



Fig. 1. represents a species that is rare. 



Fig= 2. shows the most common species. There can be 

 no doubt that this differs generically from the last. 



*Precisely such a smell is exhaled from the hituminoiis limestone ir. 

 Soathington. 



*?ee the enfl 



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