i 



i^^VWiu^ll' ^^f"" 



and its Tributaries. 31 



aerated by a longitudinal sulcation ; nose obtuse, somewhat 

 ccHiical, projecting beyond the mouth ; nostrils large, on a line 

 witK the eye. Eyes oblong-oval ; iris silvery, and slightly 

 gilt, 6n inner margin ; pupils black, operculum and preopercu- 

 lum smooth, lustre bright, silvery. Mouth diagonal, and when 

 closed th^ lower lip is nearly concealed beneath the snout. 



Body elongated, slightly compressed laterally ; bacJc rises 

 rapidly from the head to the dorsal fin, from thence to the tail 

 it slopes mora gradually and uniformly. Abdomen expands 

 beneath the pectoral fin and then continues of the same size to 

 the vent. It then rapidly diminishes to the tail. Lateral line 

 straight, except thstt near its base it curves as high as the 

 upper edge of the ope^rculum. 



Dorsal fin elevated, trapezoidal ; caudal elongated, bilobed, 

 with the tip of each lobe acute ; anal fin falls short of the 

 dorsal ; ventral horizontal, and reaches to the vent ; pectoral 

 falcate, nearly horizontal, does not attain to the ventral by 

 half an inch. 



Length 8 inches. Head 1 § inch. Tail If. Depth of the 

 body at the commencement of the dorsal fin 1|. 



Color. Back and upper surface of the body and head oli- 

 vaceous, sides silvery, and of a brilliant metallic lustre, with a 

 brownish band extending the whole length of the lateral line. 

 Pectoral and ventral fins yellowish, anal white and trans- 

 lucent. Three or four exterior rays of each lobe of the caudal 

 fin, sometimes milky and opaque, and the iritervening dusky. 

 D. 9 ; C. 23 ; A. 9 ; V. 9 ; P. 15. 



Hah. Lake Erie. 



Observations. This species is confined, I believe, to Lake 

 Erie, where it is not uncommon, and is known as the Lake 

 Minnow. ■' I formerly considered it a variety of the R.plagyrus 

 of Raf. but further observation has satisfied me that \jt is a 

 well marked and distinct species. The young, wheh two 

 inches long, are silvery and almost translucent, and are so 

 muth attenuated in their forms that they would not at first "be 

 rjecognized as any relatives of the full-grown specimens, 



