WHITEAVES. I FOSSILS OF HAMILTON FORMATION OF ONTARIO. 399 



Leda (Nuculana) perstriaUi, Hall. 1883. Ibid., pi. 47, figs. 42-44. 



Leda rosteUata, Hall. 1885. Pal. N. York, vol. V., pt. 1, Lamellibr., 2, p. 3.30, pi. 47, 

 figs. 42-47. 



A few casts of the interior of both valves of a Leda, which are so 

 essentially similar to L. rostellata in marginal outline and in the size and 

 position of the beaks that they are probably referable to that species, 

 have been collected of late years at Bartlett 's Mills by Mr. Kernahan, 

 Mr. Kearney and Mr. Schuchert. Two of these casts are in the Museum 

 of the Survey. 



Pal.eoneilo plana. Hall. 



Falwoneilo plana. Hall. 1870. Prelim. Notice Lamellibr. Shells, &c., 2, p. 7. 



M II M 1883. Pal. N. York, vol. V., pt. 1, Plates and Explanations ; 



pi. 48, figs. 21-28. 

 1885. 76h?., vol. v., pt. 1, Lamellibr. 2, p. 334, pi. 48, figs. 21-28. 



Bartlett's Mills, in the "Lower third of the section,'' a single specimen 

 (a cast of the interior of the closed valves about nine millimetres in 

 length) which was collected and identified by Mr. Schuchert. This little 

 cast is No. 26,499 of the United States National Museum Catalogue of 

 Invertebrate Fossils. 



Nyassa aeguta, Hall. 



Jfi/assa arguta, Hall. 1870. Prelim. Notice Lamellibr. Shells, (fee, 2, p. 28. 



,, II 11 1883. Pal N York, vol. V., pt. 1, Plates and Explanations : pi 



53, figs. 9-20. 

 ,1 ■ 1885. Ibid., vol. v., pt. 1, Lamellibr. 2, p. 354, pi. 53, figs. 7-20. 



A single specimen, which agi-ees very well with the description and 

 figures of this species, but which does not show any of the characters of 

 the hinge dentition, was collected at Thedford by Mr. B. E. Walker, of 

 Toronto, in 1896. 



Paracyclas lirata, Conrad. (Sp.) 



Posidonia lirata. Conrad. 1838. Rep. Geol. Surv. N. York, p. 110, pi. (no number) fig. 12. 

 Lucina (Paracyclas) lirata. Hall and Whitfield. 1872. Twenty-fourth Ann. Rep. N. Y. 



State Mus. Nat. Hist., p. 200. 

 Paracyclas lirata. Hall. (Pars.) 1883. Pal. N. York, vol. V., pt. 1, Plates and Explana- 

 tions : pi. 72, fig.s. 1-10. 

 Paraciiclas lirata, Hall. 1885. Ihid., vol. V., pt. 1, Lamellibr. 2, p. 441, pi. 72, figs. 1-19 ; 

 and pi. 95, fig. 19. 



Apparently not very uncommon at Bartlett's Mills, where specimens 

 have been collected during the last two or three years by Mr. Kernahan, 

 Mr. Kearney and Mr. Schuchert. 



