70 



Belleeophon. Species undeterminable. 



Bucania stigmosa (? J Whiteavea. .l^i. This volume, pt. 1, p. 34, pis. 5, figs. 3 



and 3 a, and 8, fig. 4 ; but perhaps not B. stig- 

 mom, Hall (1852). 



The two specimens from Gait that are doubtfully referred to Bucania 

 stigmosa on page 34, and figured on Plates 5 and 8 of the first part of 

 this volume are mere casts of the interior of the shell, that are too im- 

 perfect to be identified specifically. 



Trematonotus angustatus, Hall. (Sp.) 



Bucania ancjxistata, 'KaW. 1852. Pal. N. York, Vol. II., p. 349, pi. 84, 



figs. 7, a-d. 

 BwcaBsa OAica^oeji-sis, McChesney. 1860. Deer. N. Sp. Foss. Pal. Rocks W. S., 



p. 49. 

 Bellerophon angustata, Billings. . . . 1863. Geol. Canada, p. 34i, figs. 352, a-b. 



Tremanottts Alpheus, Hall 1865. (Jan.) Extr. in adv.of Twentieth Rep. Reg. 



N. Y. St. Cab. Nat. Hist., p. 347. (teste Hall & 

 Whitfield.) 

 Bticania Ohicagoensis, McChesney 1865. (April.) Plates illustr. K. Sp. Foss. 



Pal. Rocks W. S., pi. 8, figs. 4, a-b. 



Tremanotas Alpheus, Hall 1867. Twentieth Rep. Reg. N. Y. St. Cab. 



Nat. Hist., pi. 15, figs. 23 and 24. 



Meek 1875. Rep. Geol. Surv. Ohio, Vol. II., pt. 2, p. 



145, pi. 8, fig. 1. 

 Whi tea ves... 1884. This volume, pt. 1, p. 34. 



Gait, A. Murray, 1847, and E. Billings, 18-57 ; Guelph, E. Billings, 

 1857 ; Hespeler, T. C. Weston, 1867 and 1871 ; Elora, D. Boyle, 1880; 

 and Durham, J. Townsend, 1878-82. 



All the specimens from these localities, in the Museum of the Survey, 

 are casts of the interior of the shell. Those of adult shells almost invari- 

 ably show traces of the " interrupted oblong nodes " on the centre of the 

 periphery, that are, said to be characteristic of T. Alpheus, and most of 

 them are marked with spiral grooves on the outer volution. These " ob- 

 long nodes " on the periphery are said to be absent in B. angustata, but 

 the type of that species is stated to be a " rough cast in limestone,'' which 

 is doubtless too imperfectly preserved to sh ow them. In the writer's 

 judgment, B. angustata and T. Alpheus are names expressive merely of 

 different states of preservation of the same species. 



It is not improbable that T. angustatus itself may prove to be identi- 

 cal with the Bellerophon dilatatus of Sowerby, which is now known to 

 belong to the genus Trematonotus. However this may be, in the Museum 

 of the Survey there is a fine specimen of T. dilatatus, identified as such 

 by the late Mr. E. Billings, and showing the widely expanded outer lip of 



