39 



dorsal ; from this, in that the number of bands upon the sides is 

 much greater, the horizontal one across the operculum, here 

 present, much more marked than that beneath the eye, and that 

 the anal shares in the markings equally with the other fins. The 

 rays of the first dorsal are less in number, and the whole charac- 

 ter of the fin is different, it having a much more delicate mem- 

 brane, and being much lower in proportion to the second dorsal, 

 with which it is closely connected. The pectorals are not so 

 long in proportion as those of the Olmstedi ; the first of the two 

 spinous rays of the anal is stouter and longer than the second. 

 The form of the head, the relative position of the jaws, and their 

 length, the depth of the body as compared with the length of the 

 head ; in short, the very shape and outline of the whole fish 

 would not only characterize it as a distinct species but as belong- 

 ing to another genus. 



What this is to be is as yet doubtful. It has some points in 

 common with De Kay's Pileoma^ as defined by Agassiz in his 

 Fishes of Lake Superior, and yet more with the genus Pcecilo- 

 soma, into which it will probably fall. I have preferred, how- 

 ever, to wait until Mr. Girard shall have completed a monograph 

 of these fishes, upon which he is busily engaged, and shall there- 

 fore, for the present, simply call it an Etheostovia. 



Dr. C. T. Jackson read a description and analysis of 

 Pitch Stone, found by him at Isle Royale, Lake Superior, 

 as follows : — 



During the summer of 1847, while engaged in the United 

 States Geological Survey of the mineral lands bordering upon 

 Lake Superior, I discovered upon the shores of Isle Royale 

 some rounded pebbles and boulders of a jet black color, which 

 appeared to be identical with Pitchstone Porphyry, like that of 

 the Isle of Arran, in Scotland. 



One of these pebbles, which had been mislaid, I have found 

 since I made my Report to the Government, and have submitted 

 it to chemical analysis, which has proved my original opinion 

 to be correct, and it has been confirmed by Mr. Tesche- 

 macher. This mineral has not, so far as I know, been disco- 

 vered before in the United States. I have not had an opportunity 

 of searching for the mineral in place ^ and it is doubtful whether 



