218 IOWA GEOLOGICAL SURVEY 



jaws and setae of annelids, and occasionally a fragment of 

 crustacean. In one instance the gut was filled with seaweed. 

 . . . Another curious feature connected with feeding is that 

 Chimaera, in spite of the small size of its mouth, can injest 

 objects of large size. Thus it was found that a specimen of 

 C. colliei of moderate size, one whose mouth appeared too small 

 to admit a finger-tip, had injested a fish 6 or 7 inches in length." 



Finally, by way of recalling the ravages that a single vo- 

 racious species is able to inflict on creatures not distantly re- 

 lated to its own kind, it will suffice to mention the example of 

 the recent hammerhead shark (Sphyma zygaena). An inter- 

 esting note on the food habits of this selachian is contributed by 

 Mr. E. W. Grudger in a recent number of Science,* from whose 

 article we quote the following paragraph: 



"The stomach contained an almost perfect skeleton of a fair- 

 sized sting-ray together with many cartilaginous fragments 

 plainly having the same origin. However, the most interesting 

 thing found in the beast was the great number of sting-ray 

 (Dasyatis sayf) stings present in the body and mouth. . . . 

 I found the mouth parts to be a perfect mine of stings. In all 

 fifty were extracted, more than forty of which were imbedded 

 in the flesh adherent to the jaw cartilages. These stings varied 

 in size from perfect specimens four or five inches in length to 

 broken-off tips hardly more than one inch long. ... As 

 many as three or four tips were frequently found in a cube 

 (sic) of flesh one inch square and two inches long." 



Dipterus uddeni Eastman. 

 (Plate II, Figs. 3, 3a) 



1899. Dipterus uddeni J. A. Udden, Journ. Geol. 7, p. 494 (name only). 



1900. Dipterus uddeni C. R. Eastman, Journ. Geol. 8, p. 37, text-fig. 5. 

 1907. Dipterus uddeni C. R. Eastman, Mem. N. Y. State Mus. 10, p. 160, pi. 



4, figs. 3, 4. 



This species, which is proemial for the genus in the Devonian 

 rocks of the western hemisphere, is founded upon a unique lower 

 dental plate obtained by Professor Udden, in whose honor it is 

 named, from the base of the Cedar Valley limestone (corre- 

 sponding to the Hamilton stage of the Erian) near Buf- 

 falo, in Scott county, Iowa. Characterized especially by its 



tJune 28, 1907 (n. s. 25, p. 1005). 



