Clarke — Oneonta, Ithaca and Portage Groups. 



59 



Recent observations, on this meridian, have shown, and undoubtedly 

 future investigations will give us much more detailed evidence of the fact 

 that about these Portage sandstones, for a few feet above and below them, are 

 repeated oscillations of faunules, some of them with Naples species, others 

 with forms of later date. 



At the village reservoir, Naples, just beneath the sandstones and hence 

 at the horizon of the faunule above mentioned, occurs a species of Leptodesma 

 of distinctly Chemung aspect, though undescribed. Again, Mr. Luther has 

 recently found at the base of these sandstones in the Tannery gully several 

 interesting species of Dictyosponges. In the same section at about 100 feet 

 above the top of the Portage sandstones conies in a well defined Chemung 

 fauna, shown at Deyo basin with Hydmoceras tuberosum, ( 1 ( j r<(t<><lictij<i untni- 

 lata, Jfydriodictya, Ambocoslia wmbonatav&v. grega/ria, Spvrifer mesacostalis, 

 At/rypa ////.stria; Productella speciosa, ArtTwacantha / on the West Hollow road, 

 near Charles Sutton's, with Orthis Tioga, Liorhynchus mesacostalis, Pr<><hi< - 

 tella spmuUcosta, AmbocceUa umboiiata ; and at the Hamlin farm, with 

 ffydnoceras t/uberomm, Aniadopecten cancellatus, Sphenotus sp., AmbocceUa 

 wmbonata, var. gregaria, Stroplieodonta Cayuta, S. variabilis, S. arcuata, 

 Leptostrophia perplapa var. nervosa, Ariforacaniha. 



