240 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



the base of the Middle Cambrian in Montana, Alberta, and British 

 Columbia. 



Protolenus Matthew* occurs in the passage fauna between the 

 Lower and Middle Cambrian,' and the genus has been compared to 

 Olenopsis^ but I agree with Doctor Pompeckj * that there is not 

 much in common between them, so far as can be demonstrated by 

 the means of comparison available. 



Genus OLENOPSIS Bornemann 



Olenopsis Bornemann, 1891, Nova Acta Kais. Leop. -Carol. Deutsch. Akad. 

 Naturforscher, Bd. 56, No. 3, p. 450. (Defines and discusses genus.) 



Olenopsis Matthew, 1895, Trans. New York Acad. Sci. Vol. 14, pp. 144- 

 145. (Compares Olenopsis and Protolenus.) 



Olenopsis Matthew, 1899, Bull. Nat. Hist. Soc. New Brunswick, No. 17, 

 p. 141. (Repeats observations in paper of 1895.) 



Olenopsis Pompeckj, 1901, Zeitschr. Deutschen geol. Gesellsch., Bd. 53, 

 Heft I, p. 19. (Compares Olenopsis and Paradoxides, etc.) 



Genotype. — Olenus zoppii Meneghini [1888, Memoire R. Comitato 

 Geol. d'ltalia. Vol. 3, Pt. 2 ; Pal, dell' Iglesiente Sardegna, p. 7] . 



Stratigraphic ramgf. — The type species of the genus occurs in 

 an argillaceous shale and associated sandstones. Their thickness 

 is undetermined owing to the folding and disturbance of the strata. 



Olenopsis americanus (p. 243) ranges through about 10 feet (3 m.) 

 of shale and thin-bedded sandstones of the upper portion of the 

 Lower Cambrian or passage beds to the Middle Cambrian. 



Olenopsis agnesensis (p. 242) is limited to a band of siliceous shale 

 about 10 feet (3 m.) thick that occurs just above the Olenellus 

 canadensis zone° and beneath the Middle Cambrian. 



Olenopsis roddyi (p. 244) has been found only at one locality as 

 a single specimen in a silico-argillaceous shale of the upper horizon 

 of the Lower Cambrian in association with Olenellus thompsoni. 



It thus appears that the known stratigraphic range of the genus 

 is from the upper zone of the Lower Cambrian into passage beds 

 leading up to the Middle Cambrian. 



^ Trans. New York Acad. Sci., Vol. 14, 1895, pp. 144-145. Bull. Nat. Hist. 

 Soc. New Brunswick, No. 17, 1899, P- 142. 



* Proc. Washington Acad. Sci., Vol. i, 1900, pp. 320, 321, 325-327. 



' Matthew, 1899, Bull. Nat. Hist. Soc. New Brunswick, No. 17, p. 17. 



* Zeitschr. Deutschen geol. Gesellsch., Bd. 53, Heft i, 1901, p. 46. 

 " Smithsonian Misc. Coll., Vol. 53, No. 6, 1910, p. 318. 



