PEECID^. 45 



(3) The American Pike-perch group was called Stizostethium by Eafln- 

 esque, and (4) the Sandres of Europe were called nearly simultaneously 

 Jjucioperca by Cuvier and 8andrus by Stark. The Lucioperca marina 

 Cuv. & Val. [Perca labrax Pallas), if correctly described, has apparently 

 no affinity with the genus. 



The following analysis of the characters of these groups has been 

 compiled by Prof. Gill and myself after a rigorous comparison of the 

 several forms. It may be stated that we have been unable to ascertain 

 certainly the character of the pyloric coeca in Mimojperca and Lucioperca^ 

 the two specimens of each species in the National Museum being deprived 

 of their intestines : — 



*. Dorsal fins well separated, the interspace between them more than the diameter of 

 the eye ; the distance from the base of the last spine of the first dorsal and the 

 first of the second equal to the space occupied by the last 4 to 6 spines of tho 

 first dorsal ; anal fin II, 12, longer than high ; second dorsal I, 17, to I, 21 ; 

 spines of the second dorsal and anal closely attached to the soft rays ; last dorsal 

 spine scarcely erectile, more or less firmly bound down by the membrane ; canine 

 teeth strong (American species) : 

 t. Soft dorsal comparatively short (its base one-fourth shorter than that of spinous 

 dorsal) and with about 17 short rays ; cheeks, opercles, and top of head more or 

 less closely scaled ; body depressed, subterete ; size small ; pyloric cceca form- 

 ing two groups, the primary one of four, unequal, moderate, much shorter than 

 the stomach ; the secondary of few (1-3) rudimentary ones, which are sometimes 



atrophied Cynoperca. 



ft. Soft dorsal rather long (one-sixth shorter than spinous dorsal), with about 20 soft 

 rays ; cheeks and upper surface of head nearly naked ; body more compressed ; 

 size large; pyloric coeca three, subequal, all long (about as long as stomach), 



Stizostethium:. 



**. Dorsal tins approximated, connected by low membrane, the interspace much less 

 than the diameter of the eye ; the distance between the last spine of the first 

 and the first spine of the second only equalling the base covered by the last four 

 or fewer rays of the spinous dorsal ; spines of second dorsal and anal connected 

 with succeeding rays by loose membrane ; last dorsal spine erectile ; second 

 dorsal usually I, 22 or 23 ; anal fin at least as high as long ; body compressed ; 

 size large (European species, the body more or less distinctly transversely 

 barred and the first dorsal with series of roundish black spots): 

 X. Soft dorsal considerably (one-fifth) shorter than spinous dorsal ; anal fin II, 12, as 



long as high ; canine teeth strong ; " pyloric cceca 4 to 6 " Lucioperca. 



X\. Soft dorsal somewhat longer than spinous dorsal ; anal fin short and high ; its 

 length two-thirds its height ; its rays II, 10 ; canine teeth weak, not much dif- 

 ferentiated ; body strongly compressed as in the genus Perca; "pyloric coeca 

 three" {GUnther) Mimoperca. 



Of American species I know certainly three, the Wall-eyed Pike or 

 Yellow Pike {Stizostethium mtreum), the Blue Pike or White Salmon 

 {Stizostethium salmoneum), and the Sanger or Gray Pike {Stizostethium 

 griseum or canadense). The "Sauger" of the Saint Lawrence, S. cana- 

 dense, may be distinct from S. griseum, but at present I think it is notj 



