232 Geological Reports of the State of New York. 



Though these are maintained to hefucoidal remains in our sand- 

 stone ; it is conceded, that the "curious foot-marks," the Or7ii- 

 thichnites described by Prof. Hitchcock in the new red sand- 

 stone, " pecuharly characterize that system." p. 43. This har- 

 mony of opinion is an indication of the firm foundation of this 

 part of the science. 



The shells formerly referred to the genus Terehratula, are said 

 to belong to other and extinct genera. The mistake has not been 

 made by our own geologists alone, if mistake it is. The shell 

 remains, and a name so distinguished as that of Sowerby, sustains 

 it. True it may be, that what is now defined to be a Terehra- 

 tula^ may not exist in our rocks ; but to mention no more, Del- 

 thyris [Terehratula, Sow.) tripartita seems to be a common and 

 widely spread species, p. 35. 



A conclusion drawn from the state of the organic remains, has 

 great interest, viz. that the depositions took place "in the bed of 

 an ocean, undisturbed by violent currents or greatly agitated wa- 

 ters." This is derived from the finely preserved parts of even 

 fragile shells, only one stratum being known in the state as an 

 exception, "where the shells are in a fragmentary condition." 

 p. 26, 7. This is true also, as we know from a previous report, of 

 only a small portion of the Pentamerus in the limestone at Roch- 

 ester, the rock referred to. As in many others the " valves of bi- 

 valves are found apart," so are they in this ; often changed so 

 that the hinge is fitted to the mouth j often the valves lie cross- 

 wise ; more often piled above each other and petrified in masses, 

 the convex matched into the concave side of another valve ; often 

 entire shells with their valves unmoved ; and, often the surface 

 of the stratum and sometimes the interior, with fragments of 

 valves connected in any way. The indication of a disturbing 

 power is here considerable. Is not the evidence far greater in 

 the case of the encrinal limestone of Lockport, and the thin stra- 

 tum of it at Rochester, where the fragments of the stems of en- 

 crinites are promiscuously jumbled together, and the surface made 

 up of portions of shells, porites, encrinites, &-c. ? Beautiful speci- 

 mens of the polished encrinal limestone have been spread abroad 

 from Lockport. 



The corrections already made are not more numerous or im- 

 portant, than were to be expected from the state of geological 

 knowledge when the survey had been in considerable part made. 



