188 E. Bose — Permian of Coaliuila, N. Mex. 



mann called this series the Delicias beds and considered 

 it as pre-Permian, stating that remains of coral reefs 

 were lying nnconformably on the Delicias beds in several 

 places, and that this higher series consists of a yellowish 

 gray, solid, massive limestone, especially well exposed at 

 the Pichagua. The limestone contains the faunule 

 described by Haack, composed of the following species: 

 Cyailiaxonia gutyi Haack, C. sp., Cladopora spimilata 

 Girty, 8treptorliynclius{'l) sp. 1, S'.( ?) sp. 2, RicMhofenia 

 permiana Shumard, Spiriferina liaarmanni Haack, S. 

 hilli Girty, Rustedia meeUana Shumard, Bielasmina 

 gtiadalupensis Girty, Dielasma cf. hiplex Waagen. 



Haack also found fossils in rocks of the Delicias beds. 

 One of these he considered to be Gypidula aff. pseMdo- 

 galeata, and others are a goniatite apparently related to 

 Sporadoceras, and a tabulate coral nearly related to 

 Alveolites goldfussi Billings. In thin slides remains of 

 Foraminifera were seen. Relying on his determinations 

 of the few fossils gathered from the Delicias beds, Haack 

 referred the latter to the Devonian, but thought that beds 

 of other age might be contained in the same series. 



From the very beginning, it was e^^Ldent that the dis- 

 covery of Haarmann was of the greatest importance for 

 either the tectonics or the stratigraphy of northern Mex- 

 ico. I therefore had a great desire to visit the locality 

 myself and to study the relations between the Permian 

 and the younger rocks, as well as that between the Per- 

 mian and the supposed Devonian. Unfortunately, for 

 many years the Hacienda de las Delicias has been the seat 

 of revolutionary chiefs and a visit to it was practically im- 

 possible. However, when political conditions in that part 

 of the country improved, during the early part of the 

 summer of 1920, I made two trips to the Hacienda de 

 las Delicias and made the field studies above outlined. 

 Of my results, which differ somewhat from those of 

 Haarmann and Haack, the following statement gives a 

 preliminary account. 



My first visit was to the limestone cliif known as the 

 Pichagua, lying about 15 kilometers north of the hacienda 

 buildings and in the foothills of the Sierra del Sobaco. I 

 collected the fauna described by Haack, and other forms, 

 and soon gained the impression that the Pichagua cliff 

 was nothing other than a lenticular thickening of a lime- 

 stone bed intercalated in the Delicias series. A second 

 visit confirmed me in this belief ; I followed this limestone 



