LAMPREYS AND FISHES OF INDIANA. 151 



PetPvOmyzon concolor (Kirtland). 



Silvery Lamjirey. 



Jordan and Gilbert, 1^82, 8, 867 ; Jordan and Fordice, 1885, 1, 282 ; 

 Ichthyomyzop- argentatus, Jordan and Gilbert, 1882, 8, 10. 



Head (to first gill), in the total length seven to eight times. Dorsal 

 fin continuous, scarcely notched. About fifty muscular grooves between 

 the gills and the vent. Teeth of the supraoral lamina two. Transverse 

 row below the mouth with seven or eight teeth. All the teeth of the 

 disk simple. Color, silvery gray, darker on the upper surface. A blue 

 spot over each gill opening, even in the larvse. Length, about one foot. 



Found from Lake Erie to Missouri and north. In Indiana they have 

 been taken in White River at Indianapolis, and in the Ohio at New Al- 

 bany (/, 1877, 46); Wabash River, at Delphi (23, 1888, 43); Blue 

 River, at Wyandotte Cave (Jenkins); New Harmony (4, 1888, 162) ; 

 Great Lakes (11, 1872-3, 36); Lake Michigan (14, No. 2); Eel River, 

 Whitley County (Kirsch, 4, 1894, 86). 



Dr. Jordan (£, 758), says that this lamprey is rather common both in 

 Lake Erie and in the Ohio River. It appears to leave the deep waters 

 on the approach of spring, and to ascend the smaller streams to deposit 

 its spawn. Mr. Lewis H. McCorraick (Fishes of Lorain County, Ohio), 

 found ripe eggs in specimens on May 22. Dr. Jordan has known of their 

 being taken from Lake Erie while they were adhering to perch. On the 

 other hand, he states that they have been taken from the stomachs of the 

 perch to which the lampreys have served as food. Prof. Milner (11, 

 1872-73,74) states that this lamprey is parasitic on the lake sturgeon. 

 It is also known to attack the paddle-fish. In the Great Lakes Prof. 

 Milner states that it is found from shore to a depth of tw'enty fathoms.* 



"Pf.tromyzon oastaxeus (Girard). 



Jordan and 6ill3ert,1882, 5, 864; Jordan and Fordice, 1885, 1, 281 ; It-hthyomyzon castaneiis, 

 Jordan and Gilbert, op. cit., p. 10. 



Supraoral plate with three cusp.s. Seven to twelve teeth in the transverse row below the 

 mouth. Head with the gills contained in the total length four to five times. Muscular im- 

 pressions between the gills and the vent, fifty-six. Color, chestnut or yellowish. Length, 

 about 10 inches. 



Distributed from Minnesota to Louisiana. Not yet known from Indiana. 



This species may lie distinguished from P. concolor by the three closely approximated 

 teeth above the mouth, and by the different color. 



