xlii THE PALEONTOLOGY OF MINNESOTA. 



B. P. Whiffield. 



1880. On the occurrence of true Lingula in the Trenton limestone, by R. P. WHIT- 

 FIELD; Amer. Jour. Sci., [3], xix, pp. 472-475; June, 1880. 



The author thinks that fossils of the genus Lingula, as represented by the living L. 

 anatina Lamarck, occur in the older Paleozoic rocks. As proof of this he describes and 

 figures a new species I,, elderi from the Trenton limestone near Rochester, Minn. In 

 this form the muscular scars and vascular lines are very strong and well preserved and 

 they are found to be very similar to the same markings shown in the living species. 



G. D. Swezey. 



1882. On some points in the geology of the region about Beloit, by G. D. SWEZEY; 

 Trans. Wisconsin Acad. Sci. Arts and Letters, vol. v, (1877-81); Madison, 1882; pp. 194-204 



This paper is devoted to a description of the various strata of the Lower Silurian 

 exposed at Beloit, Wis. No particular mention of the fauna of the different strata is 

 made. The section given, is as follows: 



Galena limestone. 

 Trenton limestone. 



Upper blue, 20 feet. 



Upper buff. 



Cherty, 19 feet. 



Upper fucoidal, 3 feet. 



Birdseye, 7 feet. 



Lower fucoidal, 3$ feet. 



Carpenter, 18i feet. 



Lower blue, 18 feet. 



Lower buff, 22 feet. 

 St. Peter's sandstone. 



R. P. Whitfield. 



1882. Geology of Wisconsin, vol. IV, part III, Paleontology, by R. P. WHITFIELD, 

 Madison, 1882. 



In his preliminary remarks, professor Whitfield states : 



"Throughout the Blue and Buff limestones of the formations in southern Wisconsin the gaster- 

 opods and cephalopods characterize the formation, almost to the exclusion of brachiopods, the few forms 

 of the latter class which are common, being principally strophomenoid -forms, and mostly of three species, 

 Strophomena alternata and S. carnerata Conrad, and S. incrassata Hall or one usually referred to that 

 species. But by far the greater proportion of the organic remains of the beds consists of true mollusca, 

 Lamellibranchiata, Gasteropoda and Cephalopoda. In the upper Blue beds of the group there are usually 

 large numbers of Orthis, of two or three species, but they are mostly confined to the few feet constituting 

 this bed, which occurs immediately below the Galena beds, and but few individuals of the species occur 

 below. Among the lamellibranchiates the genera Cypricardites and Tellinomya are much the most 

 common. A few other genera are represented, but by comparatively few species and individuals. The 

 gasteropods are more numerous, but consist principally of the genera Maclurea, Ophileta, Raphistorna, 

 Trochonema, Murchisonia, Pleurotomaria, Subulites, Bucania and Bellerophon." 



Bryozoans specially characterize the Hudson River shales. 



In the enumeration of species in the Lower Silurian the term Trenton limestone is 

 made to include all the strata from the Galena to the top of the St. Peter sandstone, the 

 terms Buff and Blue being ignored. But at the special localities, the fossils are said some- 

 times to have been obtained from the " buff limestone of the Trenton group," or "from 



