289 



ceding, but is circular in tbrai. Its difimeter is about 14 lines. This prob- 

 ably belongs to a ilillerent species, and perhaps genus, from the ibrnier. 



x\nother specimen is a nearly smooth oval scale, which has been about 13 

 lines wide and 9 lines long. It exhibits obscure radiant lines on the inner 

 portion, but no granulations are evident on the outer portion. This may 

 belong to another fish than that of the preceding specimens. 



ENCHODUS. 



Enciiodus Shumakdi. 



The extinct genus above named was inferred by Agassiz from some remains, 

 consisting of jaws and teeth, found in the chalk of Europe, and was by him 

 attributed to the sphyreenoid family. Several species have been since de- 

 scribed from similar remains found in the deposits of Cretaceous age in the 

 United States. . One of these, under the above specific name, was indicated 

 Iiy a dentary bone with teeth, found by Dr. Benjamin F. Shumard in the same 

 formation in which were discovered the large scales referred to Cladocyclus. 



The specimen is rudely represented in a reversed position in Fig. 20, Plate 

 XVII. The dentary margin of the bone is 11 lines long, and contains six long 

 narrow teeth, and in the back intervals a number of minute ones. 



The first of the larger teeth is the longest, and is situated a short distance 

 from the end of the bone. Including its thickened base it is 2 lines long by 

 about one-fifth of a line wide. It is a long, narrow, straight cone, laterally com- 

 pressed, trenchant at the borders, and ends in a point with a slight posterior 

 projection or half barb. The posterior five larger teeth are situated at irreg- 

 ular distances apart, and measure from one to one and one-fiflli lines in 

 length by about one-sixth of a line in breadth at base. They are nearly like 

 the largest tooth, but are slightly more curved, and have no projection to the 

 back of the point. The minute teeth in the back intervals of the larger ones 

 and back of these arc not over the one-fifth of a line long. 



PHASGANODUS. 



PlIASGANOEUS DIRUS. 



An extinct genus of fishes sujiposed to belong to the sphyrajnoid family, 

 and nearly related with Enchodus, has been described under the above name. 

 It was inferred from a specimen of a mutilated dentary bone with teeth, 

 37 G 



