2 iv\ .i/.N .v/vir roy>'A' academy of sciences 



Colorado which conspicuously resembles the Lykins occurs in the Rico 

 formation of the San Juan region, and the Lykins and Eico are tenta- 

 tively placed in correlation, in spite of the fact that many of the Eico 

 forms are as yet not known in the Lykins and some of the characteristic 

 Lykins forms are not known in the Eico. 



The character of the Lykins formation, as would naturally be supposed, 

 changes from point to point. A well-exposed section at Heygood Canyon' 

 which is fairly representative consists, according to Mr. Butters, of sand- 

 stone and shale with some beds of sandy limestone. The sandstones are 

 pink or red and mostly soft, while the shales are red. The thickness of 

 the Lykins at this point is 816 feet. 



A little south of Heygood Canyon on the north slope of Table Moun- 

 tain were made three collections of fossils (lots 3264, 3265 and 3266). 

 They occur about 300 feet above the base of the formation and about 25 

 feet above a 25-foot bed of gypsum. They contain the same species, viz : 

 Myalina perattenuata, Myalina Wyoming ensis, Alula squamulifera and 

 Murchisonia buttersi. The matrix is a compound of fine sand and clay 

 with more or less lime, the color being a rather light brownish gray. 



Another collection was made near Stout, Colorado, from a red calcare- 

 ous sandstone (lot 3262). Only two species are present, Myalina wyo- 

 mingensis and M . perattenuata. The horizon is about 30 feet above the 

 "crossbedded sandstone" 2 in the basal member of a local group of cal- 

 careous strata 50 to 60 feet thick consisting of thin limestones, shales 

 and sandstones. 



The last collection (lot 3263) was made at Perry Park, one-fourth of 

 a mile south of the lake, in a band about 6 inches thick near the base of 

 the "crinkled sandstone." 3 The rock is whitish in color and very fine in 

 texture, apparently a mixture of lime and clay and sand. In this collec- 

 tion, I identify Myalina Wyoming ensis, Myalina perattenuata, Alula squa- 

 mulifera, Alula giTberti? and Pleurophorus sp. 



Lot 3263 occurs at a higher horizon than 3262 and recalls, especially 

 by the peculiar and characteristic species Alula squamulifera, the fauna 

 of the northern group of collections (lots 3264, 3265, 3266), from which, 

 however, it is separated geographically by a -long distance. 



The fauna of the Lykins formation is, so far as known, very limited, 

 consisting of only six species, and in addition to describing the two spe- 

 cies, which are new, it has seemed desirable to remark briefly upon the 

 other forms. 



2 Colorado Geol. Survey. First Report, pp. 168-9. 1909. 

 3 U. S. Geol. Survey, Bull. 265, p. 25. 1905. 



