184 Lee — Lower Paleozoic Rocks of Central New Mexico. 



300 feet of cherty limestone is exposed at the foot of the cliffs. 

 The rocks are continuous with the upper chert (No. 3) of the 

 Red Cabin section and yielded the following fossils : 



JPetraia, sp. undet. (near Streptelasma profundum (Black 

 River) and 8. calicularis (Silurian)). 



Lindstromia, sp. no v. 



Orthis, near davidsoni and flabellum. 



Dalmanella (f Schizophoria), sp. undet. 



Clorinda? sp. undet. 



Atrypa sp. nov. (near Zygospira put ilia and Atrypa margina- 

 lis). 



? Eitomphalus sinuatus (Hall) Foerste (Clinton species). 

 Lophospira, sp. undet. 

 Trockonema " -" 



Eunema, near robbinsi, a Trenton form. 

 J^oxonenia 

 Nucleospira f 



Ulrich states that all of the fossils from near Red Cabin, 

 with the exception of the two lower Ordovician forms, belong 

 at the same general horizon and are of Richmond or late Ordo- 

 vician age, and suggests that the absence of fossils indicating 

 Ordovician horizons intervening between this and the early 

 Ordovician rocks below the uncomformity " probably points to 

 conditions similar to those prevailing in the vicinity of El Paso 

 75 miles to the south, where the Richmond commonly rests 

 directly on Beekmantown." Since a lower Ordovician chert 

 occurs unconformably below the Richmond in the Red Cabin 

 section, and this in turn rests upon a massive quartzite that is 

 not represented in the Shandon section, it is probable that the 

 apparent conformity of the Cambrian and Ordovician in that 

 section is deceptive and that a time interval of considerable 

 duration is represented between the two formations. 



According to Ulrich, there are certain elements in the faunas 

 that suggest Silurian rather than Ordovician age, but, except- 

 ing the two early Ordovician species, he is inclined to regard 

 the fauna as representing one of the phases of the Western 

 Richmond. He states that " very few of the species are closely 

 related to ordinary described American forms, but they are 

 very similar and perhaps identical with species occurring in the 

 Borkholm limestone of the Russian Baltic Provinces. In the 

 absence of authentic examples of the Russian species, I hesi- 

 tate as yet to identify these New Mexican fossils with them. 

 The associated coral bed represented west of Red Cabin, how- 

 ever, is widely distributed in America west of the Mississippi 

 and occurs also in the Island of Anticosti. Its position is 

 within the upper part of, or just above, the Maquoketa shale 

 of the Mississippi Valley. The highest horizon represented 



