WHITEAVES.J DEVONIAN FOSSILS, MACKENZIE EIVER BASIN. 221 



Spiripera disjuncta, Sowerby. 

 Plate 29, fig. 4. 



Spirifera disjuncla, Sowerby. 1840. Trans. Geol. Soc. Lond., 2nd Ser., vol. V, pi. 

 liii, fig. 8, and pi. liv., figs. 12-1:!. 

 " calcarata, Sowerbj'. Ibid., pi. liii, fig. 7. 

 " extensa, Sowerby. Ibid., pi. liv, fig. 11. 

 " gigantca, Sowerby. Ibid-, pi. Iv, figs. 1-4. 

 " inornata, Sowerby. Ibid., pl. liii, fig. ii. 

 Spirifera Vnrnniilii, iMurchison. 1840. Bull. Soc- Geol. France, vol. XI, p. 2.52, 



pl. ii, fig. 3. 

 Spirifera difjvncta, Davidson. 1865. Mon. Brit. Itev. Brach., pp. 23 and 24 

 (which see for a complete list of synonyms of Britisli and 

 European specimens of this series), pl. v. figs. 1-12 and pl. 

 vi, figs. 1-5. 

 Spirifira difjuncta, Hall. 1867. Pal. N. Y-, vol. IV, pis. xli, and xhi, and 

 Walcott, 1884, Pal. Eureka distr. Nevada, p. 134 [which see 

 for list of synonyms of N. American specimens). 

 Spirifera Kennicotli, Meek. 1860. Trans. Cliicago Ac. Sc, vol. I, p. 101, pl. xiv, 

 fig. 9. 



Peace River, at Fossil Point, A. R. C. Selwyn, 1875: a few badly 

 preserved specimens. 



Hay River, forty miles above its mouth, R. G. McConnell, 1887 ■ 

 abundant and in tine condition. Peace Rivei', at Vermilion Falls, R. 

 G. McConnell, 1889 : six specimens. 



At these localities, and especially at the latter two, most of the 

 specimens collected belong to the tj-pical form of the species, or at anj' 

 rate to that which Davidson regarded as such and illustrated under that 

 name on Plate v. of his " Monograph of the British Devonian Brachio- 

 jjoda.'' In this form, no matter what the mai-giiial outline of the shell 

 may be, the umbo and beak of the ventral valve are appressed and 

 incurved, while its area, which is coneavely arched and nearly vertical, 

 is very narrow in the direction of its height. 



As will be seen upon i-eference to the synonymj^ quoted, this very 

 variable .■^pecies was described in 1840 by no less than six different 

 specific names, and it is still doubtful which of these should be retained. 

 Although here called Spirifera disjuncta, Sowei-by, on account of the 

 veiy general usage to that effect, especially in American publications, 

 it would seem that the proper name of the species is S. Verneuilii, Mur- 

 chison. In Davidson's monograph (op. cit.), although the species is 

 at first called S. disjuncta in the text, yet, in a foot note to page 100, 

 the following very explicit statement is made: — " From having unfor- 



