FOSSILS OF THE BURL1XGTON GEOUP. 441 



eating series on the baseband on each tipper lateral space, on 

 each side, another series rims up and down, parallel to the 

 lateral margins. Column rather small, round, and provi- 

 ded with a very minute central perforation. 



Hight of body to top of first radials, 0.65 inch; breadth, 

 0.66 inch; hight of base, about 0.30 inch. 



This species seems to be somewhat intermediate in its characters 

 between I), oratux and D, striatua, of Owen and Shuinard. From the 

 first it differs in having distinct, sharply defined, continuous lines on 

 the body plates instead of merely rows of depressed granules, and these 

 Jines also run differently on the basal pieces from the rows of granules 

 on that part of D. oratun which are described as forming a series of 

 hexagons, one within the other, instead of forming three series of tri- 

 angles, as the lines on our species shows a tendency to do. The lines 

 are also as well defined on the radial and anal pieces of our species as 

 on the base, while the surface of these parts of 1). oratus is described as 

 being merely " corrugated." 



In having continuous, well defined, raised lines, it agrees more nearly 

 with 1). uti-Uitus, of Owt?n and Shuinard, but it is easily distinguished 

 from that species b} T having these lines very much finer and moic 

 crowded, as well as greatly more numerous, there being about ten of 

 them in the space of 0.20 inch, which only includes four or five of those 

 on D. striatus. 



Locality and position Lower Burlington beds, Burlington, Iowa. 

 Lower Carboniferous. Mr. WACHSMUTH'S collection. 



PisuM, M. and W. 



PI. 3, Fig. 2. 

 Dichocrimis pisum, MEEK and WORTHEX. Proceed. A.cad. Xat. Sci., Phila., 1869, p. 69. 



BODY small, somewhat cup-shaped, approaching sub- 

 globose, rather depressed or flattened below, and from one- 

 fourth to one-third longer than wide, slightly contracted at 

 the top. Base nearly flat, or presenting a shallow dish- 

 shaped, subcircular outline ; facet for attachment of the col- 

 umn very small. First radial plates generally slightly 

 longer than wide, and nearly quadrangular in form, com- 

 paratively moderately thick ; sinus in the upper margin of 



