188 LETTERS FROM PROF. AGASSIZ. 



article, to talk over with you all these critical species. I 

 have myself two undescribed ones from the lakes, one 

 from Chicago and Milwaukee, the other from Buffalo, and 

 several others from Southern New York, &c. Leuciscus 

 elongatus, seems to me from the description, also to belong 

 to the genus. I expect that your Leuciscus Stoverianus 

 will belong to a new genus I have lately established for a 

 species from Tennessee. I am therefore particularly 

 anxious for that species, as indeed for everything you have 

 touched upon. 



Will you be able to let me have some specimens of your 

 Pocilichtys erythrogaster and your new Alburnius also, 

 and do you want any of the new species and genera I have 

 established. 



With great regard, Yours Very Truly, 



L. Agassiz. 



Dr. J. P. KiRTLAND. 



My Dear Sir: 



I lost no time in making a careful comparison 

 of your figure and description of Esox Estor and my Boreus, 

 I am sorry to say I have no specimen of your Estor, so that 

 I could not make a more direct comiDarison, However, 1 

 am satisfied they are not identical. My Boreus has a less 

 forked tail, and the lobes not acute. The spots upon the 

 sides of the body are totally different. Boreus has few 

 evanescent white spots, especially backwards, w^hilst your 

 Estor is spotted all over, and, as you say, the spots are 

 brownish. Moreover, the dorsal of Boreus is markedly 

 larger than the anal and like this spotted, the spots assum- 

 ing an arrangement which makes them appear like bands 



