144 LAND AND FRESH WATER MOLLUSKS 



This unfigured species has been regarded by Roper as only a muta- 

 tion of C. abdita Haldeman. 



Comeocyclas ultramontana Prime. 



Pisiiiium ultramontanum Prime, Mon. Am. Corbie, p. 75, 

 fig. 85, 1865. 



Range. — Canoe Creek, California ; Seattle, Wash. ; 

 Nanaimo, Vancouver Island, and Pender Island ! British 

 Columbia. 



Comeocyclas arctica Westerlund. 



Pisidiwn arcticum Westerlund, Vega Exp. Vetens. lakt., iv, p. 217, 1885. 

 Range. — Port Clarence, Alaska. 



Comeocyclas nivalis Westerlund. 

 Pisidium nivale Westerlund, op. cit., p. 218, 1885. 

 Range. — Port Clarence, Alaska. 



Comeocyclas glacialis Westerlund. 

 Pisidium glaciale 'VJKSTKvaAm'D, op. cit., p. 218, 1885. 

 Range. — Port Clarence, Alaska. 



* Comeocyclas sibirica Clessin. 



Pisidium sibiriciim Clessin, K. Svenska Vet. Ak. Forh., p. 70, fig. 23, 1877 ; 

 Mon. Pisidium, Conch. Cab., ed. 11, pi. vii.figs. 15-17, 1877. — Wester- 

 lund, Fauna Pal. Reg., vii, p. 23, 1890. 



Range. — Western Siberia, on the Yenisei River to 60° 50' N. Lat., 

 1 Port Clarence, Alaska. 



* Comeocyclas borealis Clessin. 



Pisidium boreale Clessin, in Westerlund, Fauna Pal. Reg., vii, p. 32, 1890. 



Range. — Western Siberia at Lusino. .? Port Clarence, Alaska. 



The preceding five species are ascribed to Port Clarence on the 

 authority of the literature solely. I have not seen specimens of any 

 of them. I suspect that the C. sibirica and borealis reappear in the 

 form of new species, among the three nominal species preceding them. 



Comeocyclas pulchella Jenyns. 



Cydas pulchella Jenyns, Trans. Phil. Soc. Cambridge, 1832, p. 306, pi. x, 

 figs., 1812 ; not of Deshayes, 1835, nor Gassies, 1849. — Sowerby, in 

 Richardson, Fauna Bor. Am., ill, p. 316, 1836. 



Range. — Middle and Northern Europe to 69° N. Lat. Arctic 

 America .' 



Methy Lake, Athabaska (Richardson). 



