WHITEAVES.] DEVONIAN FOSSILS, MACKENZIE RIVEll BASIN. 223 



the oj'iginal description of S. cyrtinmformis the suiface of the valves is 

 said to be " marked by about forty five to fifty low, rounded plica- 

 tions, whereas in the specimen from the Hay River there are only 

 twenty nine or thirty. This ilifforonce, however, can scarcely be re- 

 garded as of specitic importance. 



& cyrtinwformis is very closely allied to the S. Utahensis of Meek,* 

 which Mr. Walcott places among the synonyms of S. disjuncta. On 

 the othei- hand, S. cyrtinaformis appears to the writei- to be specifically 

 identical with the fossil from the Bifel which D'Archiac and DeVerncuil 

 described and figured under the name S. aperturatiis, vai. cuspidatus. 

 In his Monograph of the British Devonian Bi'achiopoda (page 26) David- 

 son says that (S. aperturatus i< a synonym of S. cannlifera, Valencien- 

 nes (in Lamarck's Hist. Nat. des Animaux sans Vertebres), but makes 

 no reference to D'Archiac and DeVerneuil's description and figures of 

 <S^. aperturatus and its var. cuspidatus. He farther states (op. cit., p. 26) 

 that '' Sp. canalifera has much of the general shape of S. disjuncta, but 

 will be easily distinguished on account of the bifurcation of its lateral 

 ribs, a feature not observable in S. disjuncta." According to Prof. Hall, 

 in S. cyrtinceformis '■ the central plication on the mesial fold and sinus 

 divides once or twice before reaching the front of the shell ; the other 

 jilications ai'o simple." 



Spiripera sdbattenuata, Hall. 



S'jiirifi:ra indet. Owen. 1852. Rep. Geol. Surv. Wiscona., Iowa and Minnes., pi. 



iii, tig. 9. 

 Sjjirifer submwro'iiatus, Hall. 1858. Geol. Rep. Iowa, vol. I., pt. 2, p. 50-t (but as 



this name was found to be preoccupied it was changed to S. 



suhattenuata on "p. 3 of the index), pi. iv, figs. .3a, b, c. 



Athabasca Eiver, — opposite La Saline, Dr. R, Bell, 1882, a few small 

 specimens, — three miles below the Calumet River, R. G. McConnoll, 

 l>yO, three specimens, — and thirt3' miles below Red River, R. G. Mc- 

 Connell, 1890, two specimens. 



Spirifera inutilis. Hall. 



Spiri/er iinilil'h, Hall. 1858. Geol. Rep. Iowa, vol. t, pt. 2, p. 505, pi. iv, figs. 

 4a, b, c. 



Localities, collectors and dates the same as for the preceding species : 



• See Col. Simpson's Kep. Expl. acr. Gre.^t Basin of Utah, 1876, p. 345, pi- i, figs. 4, a, b, o, and 

 r. S. Geol. E.xpl. Fortieth Piirallol, vol. IV, 1877, p. :i!l, pi. iii., figs. 1. la-e. 



