2q6 ' NEW YORK STATE MUSEUM 



There was present also the little phyllopod, Estheria membranacea, 1 

 which is elsewhere known only in the old Devonic lakes of Scotland and 

 Russia, but, on the whole, invertebrate animal remains are most unusual in 

 these sediments. The fact that ingress of salt water into this lagoon 

 occurred at times, probably of storm and heavy tidal flow, is shown by the 

 presence of shells of Orthoceras standing vertical in great numbers 2 in 

 certain strata, where they were evidently floated in by inrush from the deep 

 waters without, dead or killed by contact with the fresh water. 3 Large 

 quantities of terrestrial vegetation, Lepidodendron, ferns (Archaeopteris, 

 Psaronius) were washed down into this lagoon. Apparently the low shores 

 of the land were transgressed in some measure by the spreading lake 

 waters, as indicated by the stumps of fern trees which have been found in 

 place in the lower sediments. In this lagoon fish characteristic of Old Red 

 lake conditions also flourished (Bothriolepis, Holoptychius, etc.). Indeed, 

 the conditions of deposition so far as indicated by the organisms therein 

 contained, were altogether similar to those prevailing in the formation of 



•Clarke. N. V. State Pal. Rep't 1900. 1901. p. 103. 



'Following the arguments presented by Jaekel (Zeitschr. d. deutsch. geol. Gesellsch. 

 1902. 54:67-101) for the attached condition and erect growth of Orthoceras, it has been 

 suggested by Beushausen (he. cit.) that these occurrences of vertical Orthoceras in the 

 Oneonta sands, which are the only ones recorded of these shells in such position, may be 

 due to the accumulation of sediments about the organisms while still attached to the bot- 

 tom. Aside from other considerations which would tend to show that while Orthoceras 

 may have been sedentary in its habit it was not affixed by its apex, the physical 

 conditions involved in the instances cited seem to require a modification of this interpre- 

 tation. Granted that these bodies of littoral habit were buried in the marine sediments 

 on the outer or seaward side of the submarine barrier, it is readily conceivable that an 

 excessive outflow of fresh waters carrying them beyond their proper boundary would kill 

 outright an entire settlement of these creatures, and would have -washed into close prox- 

 imity with them remains of Archanodon and terrestrial plants such as characterize the 

 true Oneonta deposits. The position of these marine bodies is on the remote western 

 boundary of the lagoon during its earlier stages, and their occurrence evinces the insta- 

 bility of the barrier separating the marine or outer fauna from that within. 

 3 Clarke. N. Y. State Mus. Bui. 39. 1900. p. 167. 



