386 [August, 



The Committee on the following papers by Mr. Grirard, reported in 

 favor of publication in the Proceedings. 



Observations upon the American species of the gemcs Esox 



By Charles Girard. 



The genus Esox is represented in North America by quite a large number 

 of species, commonly called " pikes " or '* pickerels," without any discrimi- 

 nation. The same species of Esox may be called here "pike,'' and elsewhere 

 ' pickerel." 



When we first undertook the study of these fish, we were at a loss to know to 

 which species might be strictly applied either of these vernacular names. We 

 asked fishermen, some of them very intelligent, what the difference in their 

 mind was, when calling a certain Esox a pike, and another a pickerel ? They 

 knew of no difference, but that when a pike was spoken of they understood 

 the very large individuals, whilst the small ones were the pickerels, the young 

 of the preceding. 



In examining comparatively Esox estor and Esox reticiilatusy of Lesueur, 

 amongst other differences, it will be perceived that in one {E. estor,) the cheeks 

 and opercular apparatus exhibit a perfectly smooth and naked sk:n, whilst in the 

 other {E. reticulatns) these same parts are scaly all over. 



In tracing the character throughout the range of the species we find naked 

 cheeks and opercular apparatus in the maskallonge (-B. vobilior, Thomps.) in 

 the pike of Lake Superior, {E. boreus, Ag.) and in several others still confounded 

 w'iih. Esox estor oi Lesueur. On the oihexhdiX'id, Esox americauiis, Lacep. {E.niger 

 Lesn.) E. fasciatus, Dekay. E^ clathratus, Bd., MS., resemble Esox reticulatus 

 in having the cheeks and opercular apparatus covered with scales. 



Consequently there are two groups of species in the genus Esox, based upon an 

 organic difference, and for which we have two distinct names. The maskallonge 

 and allied species we ought henceforth to call Pikes ^ retaining the name oi Pickerels 

 for Esox reticulatus and allied species. 



The pikes, when full grown, are the largest of the genus ; amongst pickerels, 

 we find the smallest species. Esox reticulatus is the largest pickerel known, and 

 it is as larae as any of the specimens of Esox boreus which we have seen. 

 We would nevertheless be inclined to think that the latter reaches a much larger 

 size. 



The organic difference which we have pointed out between the pikes and 

 pickerels, corresponds to a curious fact in their geographical distribution in 

 North America ; the Pikes being confined to the great lakes and western waters 

 generally, whilst the Pickerels occur in such ponds and rivers whose waters 

 empty into the Atlantic. 



A pike has been introduced into the Connecticut river, and the fact that it has 

 multiplied there, is no objection to this general law of their distribution. 



A Pickerel is said to occur in the Ohio river. We have not seen any specimen 

 of this fish, the history of which ought to be carefully investigated. If a pickerel 

 was originally an inhabitant of that body of water, then we shall have one ex- 

 ception to the general rule. 



Lesueur has indicated under the names of Esox vermictilatus, E. lineatus and 

 E. depraudus, three species of the genus Esox from the Wabash river. As no 

 specimens are preserved any where, it will be difficult to identify them, even 

 upon visiting the place where they occur. But one feature can be easily deter- 

 mined, that is whether their cheeks and opercular apparatus are or are not 

 covered with scales. Any traveller will be prepared to make this observation. 

 Lesueur's Esox lugubrosus, from the eastern states, and Esox phalerutus, of 

 Say, from Eastern Florida, are likewise undetermined in this respect. 



