﻿Fucoids of the Cincinnati Group. 



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called R. carbonarius. It is quite small — about a quarter of an inch wide 

 and but little longer, with the groove separating the lobes to a considerable 

 extent. The other is R. acadius. This is longer, sinuous, with a deep 

 line in the center and the elevated sides cut into small pieces by deep cross 

 lines. The name of Principal Dawson can not be well used for such forms 

 as Professor Hall has described, the name Cruziana of D'Orbigny being 

 much the oldest of all. The last species, R. acadius, differs so much from 

 the others that it can scarcely be included in the same genus. 



Having noticed all the species of the genus known from America, a new 

 species is here described. 



Cruziana Carleti, N. Sp. (Plate 8, figure 1.) 



Form elliptical, a little longer than broad; longitudinal furrow, extend- 

 ing almost from one end quite to the other, and there separating the lobes ; 

 center of the furrow broadened from a mere line out into an oval, about 

 three, quarters of an inch wide and one and one-half inches long; and then 

 narrowing to the lower end, where it again flares out. Inside of this oval, 

 on each side of a furrow in the center, are seven or more small ridges, sepa- 

 rated by corresponding depressions. The upper end of the fossil is 

 rounded; the lower is separated into two parts, each of which is rounded 

 off in a regular manner ; the tops of the lobes are nearly smooth, without 

 any transverse rugae. 



This species differs from all the other described species, in being entire 

 at one end and separated into two lobes at the other ; and also, and espe- 

 cially, in having the seven or more pairs of elevations and depressions ar- 

 ranged in an oval in the center of the longitudinal groove. 



The description is drawn from a specimen in the collection of the Cin- 

 cinnati Society of Natural History. Mr. U. P. James has another and very 

 similar' one. His is wider and not so long in proportion, and the central 

 oval is correspondingly broader and has ten instead of seven depressions. 

 The specific name is given in honor of Mr. S. T. Carley, who presented 

 the specimen to the Society a number of years ago. He collected it in the 

 rocks of the Cincinnati group near Bantam, Clermont County, Ohio. 



Character of Cruziana. 



The fossils described under Rusophycus and Cruziana have been consid- 

 ered as belonging to the Algae. Hall, Billings, White, Miller and others have 

 so placed them. Dana, in his Manual of G-eology (page 225), speaks of 

 them as trails of articulates ; and Dawson, in Acadian Geology, calls them 

 impressions of trails of trilobites. 



That they are not fucoids may be considered as settled definitely, and 



