2 86 NEW YORK STATE MUSEUM 



while it is unquestionably O. suborbicularis, this opinion indicates 

 the approximation of these species. 



Habitat. Genesee province ; Naples subprovince. Ontaria sub- 

 orbicularis is a very common shell in the lower soft shales of the 

 Naples beds in Yates, Ontario, Livingston, Genesee and Erie counties and 

 also occurs in the Styliola limestone on Canandaigua lake. 



With Phragmostoma natator, Manticoceras intumes- 

 cens and Buchiola retrostriata it rises high in the strata in the 

 region about Elmira surviving after the introduction of the brachiopod 

 fauna. 



It is doubtful if any of the shells found in the Chautauqua subprovince 

 can be safely referred to this species. Such forms are not frequent in any 

 event and when well preserved seem to represent other species, e. g. 

 O. concentric a, O. pontiaca. 



Ontaria concentrica von Buch (sp.) 



Plate 8, fig. 26 



Orbicula concentrica v. Buch, Ueber Goniatiten. 1832. p. 50 



Cardium pectunculoides d'Archiac & de Verneuil, Geol. Soc. Trans, ser. 2. 



v. 6, pt 2. 1842. p. 375, pi. 36, fig. 12 

 Cardiol a concentrica Keyserling, Beob. (ib eine Reise in das Petschoraland. 



1846. p. 253 

 Cardium pectunculoides A. Roemer, Verst. des Harzgeb. Beitr. 1. 1850. 



p. 26, pi. 4, fig. 10 

 Cardiol a concentrica Sandberger, Verstein. d. rhein. Schichtensyst. in Nassau. 



1850-56. p. 272, pi. 29, fig. 1 

 Cardiol a? concentrica Tschernyschevv, Fauna d. mittl. u. ober. Devon am 



Westabhange des Urals. 1887. p. 18, pi. 6, fig. 15 

 Cardiola concentrica Beushausen, Lamellibr. des rhein. Devon. 1895. 



P- 355, Pi- 37, fig- 16-20 

 cf . Lucina wyomingensis Williams, U. S. Geol. Sur. Bui. 41. 1887. p. 44, 



Pi- 3, fig- 13 



I refer with a little hesitation to this old species the single valve here 



figured, which presents an expression not attained byO. suborbicularis 



in the three or four strongly marked plications behind the beak and finer 



