FEATURES OP FORT DODGE GYPSUM 



589 



compared the unquestionably identified species vnih Pennsyl- 

 vanian and with Permian lists and all point to the former rather 

 than to the latter. Not a trace of anything Mesozoic occurs in 

 the material. Some of the specimens show evidence of wear as 

 from rolling but they do not seem to have been transported far. 

 Here is the list: 



Fusulina secalica Say=jP. cylindrica Fischer. 



Zap'hrentis (species unidentified). 



Stem segments (and plates?) of unknown crinoids. 



Rhombopora lepidodendroides Meek. 



Productus cf. longispinus Sowerby. 



Pugnax osagensis (Swallow). 



Squamularia perplexa (McChesney). 



Fig. 196. — The general even top of the gj-psum in the Vincent clay pit, Fort 

 Dodge. Note the channel down the center of the view. 



The Rhpmbopora has suifered from wear so that the charac- 

 teristic markings, if they were ever present, are rubbed off. 

 There is no question about the Fusulina. I sectioned a few, they 

 are as good specimens as one could wish for. ' ' 



The nearest known rocks of Missouri age are in Carroll, Craw- 

 ford and Monona counties. In former times the northward ex- 

 tent undoubtedly was greater. Cretaceous rocks are present only 

 a few miles to the west of Fort Dodge in Calhoun and Poca- 



