WHITEAVES.] DEVONIAN FOSSILS, MACKENZIE RIVER BASIN. 213 



to end : apertures of the cells nearly terminal, extremely minute, 

 simple and consisting of mere rounded perforations in the cell wall. 



Surface smooth. 



Hay River, forty miles above its mouth, E. G. McConnell, 1887: four 

 specimens each parasitic upon Orthis striatuki. 



This interesting little species is very closely allied to the Hippothoa 

 devonica of (Ehlert,* from the Devonian rocks of the Department of 

 Mayenne, France, and perhaps should be referred to that genus rather 

 than to Stomatopom. Its cell apertures are so minute that they can 

 scarceljr be seen with an ordinary simple lens, but their characters can 

 be made out without much difiiculty under an achromatic microscoj^e 

 with an inch and a half objective. 



ASCODICTYON STELLATUM, Nicholson. 



Ascodictyon stiUafuin, Nicholson. 1877. Annals and Mag. Nat. Hist., 4th Ser., 

 vol. XIX, p. 464. 



East bank of the Clearwater River, about five miles below the Pem- 

 bina, Professor Macoun, 1815 : two or three specimens, attached to 

 Orthis striatula. Hay Eiver, forty miles above its mouth, E. G. Mc- 

 Connell, 1887; one specimen on a worn fragment of shell. Athabasca 

 Eiver, thirty miles below the Eed Deer Eiver, and three miles below 

 the Calumet, E. G. McConnell, 1890: five specimens from the first of 

 these localities and four from the second, all attached to 0. striatula. 



The discovery and recognition of this diminutive little species at 

 each of these localities is due to Mr. L. M. Lambe. 



Palesciiara quadrangularis, Nicholson. (Sp.) 



Chxteies qurMtrangulrtrig, Nicholson. 1874. Geol. Mag., N. Ser., Decade 2, vol. I, 



p. 58. 

 Chatetes 'jvadmngularls, Nicholson. J 874. Rep. Palteont. Prov. Ontario, p. 61, 



fig. 18. 

 Palesciiara quadrangularis, S. A. Miller. 1889. N. Amer. Geol. and Palfeont., p. 



177 (under Clixtetes). 



Hay Eiver, forty miles above its mouth, E. G. McConnell, 1887 : four 

 specimens, one on Orthis striatula, one on Spirifera disjuncta and two on 



* Bulletin de la Soci^te d'Btudes Soientiflqiios d'Angers, ann^e 1887. 

 May, 1891. 



