E, M. Kindle — Silurian Fauna in Western America. 127 



land,* and Australia. f This fauna occurs in a magnesian 

 limestone of considerable thickness — probably 2,000 feet. It 

 is preceded in the section by Ordovician limestones containing 

 Maclureas. It is followed by a somewhat later phase of the 

 Silurian and by the Devonian. 



Another but smaller Silurian fauna has been found in south- 

 eastern Alaska, on Kuiu Island, nearly a thousand miles south- 

 east of the Porcupine Hiver locality. It contains : 



Diphyphyllum ? sp. 

 Conchidium Tcnighti (Sow.) 

 Whitfieldella sp. 

 Holopea cf. servius Barr. 

 Murchisonia sp. 



None of the species is abundant, with the exception of G. 

 Tcnighti, which is represented by great numbers of large shells. 

 C. Tcnighti is one of the characteristic fossils of the Aymes- 

 try limestone of the Ludlow group of England. It is known 

 also from Russia and Bohemia. There appears to be no 

 authentic records of its occurrence in the Silurian faunas of 

 the United States. The nearest equivalent of this fauna in 

 eastern America is the Niagara fauna. While none of the 

 species' collected are identical with Niagara species, Conchid- 

 ium Tcnighti is very closely related to C. nysius of the Niag- 

 aran fauna. 



The Kuiu Island fauna occurs in the midst of a limestone 

 series which appears to be 2,000 feet or more in thickness. 

 Other portions of the series which were examined appeared 

 to be barren. Upward these limestones seem to terminate 

 with volcanic breccias, while below they pass into cherts and 

 argillites of undetermined age. 



Utah fauna. — The third locality to which attention is in- 

 vited is in the Wasatch Mountains, in northeastern Utah4 In 

 Green Canyon, east of Cache Valley, the following fauna was 

 obtained : 



Favosites gothlandica Lamarck 



Ftvosites cf. niagarensis Hall 



Ilalysites catenutaria Linn. 



Zaplirentis sp. 



Pentatnerus oblongus Sow. 



This fauna, though containing a small number of species, is 

 represented by a great number of individuals. Pentamerus 

 oblongus is the most abundant species. The presence of this 



* Quart. Jour. Geol. Soc. London, vol. xli, p. 199, 1885. 

 fMem. Geol. Surv. N. S. Wales, Pal., No. 6, 1898. 



\ The writer is indebted to Mr. F. B. Weeks for information regarding 

 the location of sections in this region. 



