NATURAL SCIENCES OF PHILADELPHIA. 1G3 



Measurements of two Mississippi specimens are as follows : 



Length of crown internally 11 lines. 8 lines. 



Breadth " " 16^ " 13 " 



Length of tooth at middle 14 " 10 " 



Breadth of root . " 18 " 14 " 



Measurement of two Kansas specimens are as follows : 



Length of crown internally 8 lines. 6 lines. 



Breadth " " 15| " 12 



u 



Length of tooth at middle 12 " 8 



(< 



Breadth of root " 17 " 13 " 



ACRODUS HTJMILIS. 



Founded on a tooth adherent to a portion of limestone from 

 the New Jersey cretaceous formation. It resembles most nearly 

 the Acrodus rugosus, Ag., of the chalk of Maestricht, and the A. 

 polydictyos, Reuss, of the Bohemian chalk. The tooth is 8 lines 

 wide, 2 lines fore and aft. The anterior and posterior borders are 

 not quite straight ; and the extremities are angular. The upper 

 surface is moderately convex. A nearly obsolete ridge crosses the 

 tooth transversely, and from this ridge minute folds are directed 

 forward and backward to end in a reticulation. 



This is I believe the first time the genus Acrodus has been 

 noticed in the American cretaceous formation. Prof. Emmons 

 represents the tooth of a species in his report of the North Caro- 

 lina Geological Survey, p. 244, fig. 97, which he attributes to the 

 miocene. If really an Acrodus tooth, it would be the latest spe- 

 cies 3 r et discovered. It might be named Acrodus Emmonsi in 

 honor of its discoverer. 



Pycnodus faba. 



This species is named from a specimen from the cretaceous for- 

 mation of Mississippi, discovered by Dr. William Spillman. The 

 fossil consists of a jaw fragment with four large teeth obliquely 

 parallel with each other. They are elongated elliptical, and 

 smooth ; and they measure three-fourths of an inch wide, and one- 

 fourth of an inch in the short diameter. On both sides the larger 

 teeth, there are two rows of small teeth. 



Mr. Norris spoke at some length on his effort now in progress 

 to stock the Delaware with the true salmon (Salmo sala?-). Having 

 procured 12,000 ova from Mr. Wilmot, New Castle, Canada, he 

 placed then on gravel in wooden troughs of running spring water 

 near the town of Easton, Pa. These ego-s was taken in November, 

 1871, by manipulation of the parent fish and fecundated in the 

 usual wa} r , and placed in water almost down to the freezing point. 

 The young fish were, however, plainly visible in the egg when 

 received on the first of April, and struggling to break the shell. 



