552 PROCEEDINGS OF THE ACADEMY OF [UeC, 



Elk Creek (Chester Co.); Conestoga Creek and near Denver (Lancaster 

 Co.); Emporium (Cameron Co.): Youghiogheny R. and Meadow 

 Rmi near Ohio Pyle (Fayette Co.); Beaver R.; Kiskiminitas R. ; 

 Newcastle (Lawrence Co.); Allegheny R. basin (Warren Co.). 



This beautiful fish occurs in all streams west of the Alleghanies, and 

 I have only met with it in the Susquehanna, in the Atlantic basin of 

 our limits. It is said to reach 10 inches in length and be a fair table 

 fish. Most frequently it is found in the larger creeks and rivers, sel- 

 dom occurring in small broolcs. It will take the hook readily and is a 

 good bait as it is hardy. It shows considerable variation, the young 

 being quite unlike the adult, and the latter also differing in the spawn- 

 ing season, which takes place in late spring and early summer. 



Exoglossum maxillingua (Le Sueur). 



Head 3f to 4^; depth 3| to 4^; D. usually iii, 7, i, rarely iii, 8, i; 

 A. usually iii, 6, i, rarely iii, 7, i; scales usually about 48 to 51, 

 rarely 39, 43, 44, 45, 47, 52, 53, 54, 56, 57 + usually 3, frequently 2, 

 rarely 4; scales above 1. 1. usually 10, frequently 9, seldom 11, rarely 12; 

 scales below 1. 1. usually 6, frequently 7; predorsal scales usually 25 to 

 28, sometimes 29, rarely 30; snout 2f to 3^ in head; eye 2f to 4f ; 

 maxillary 2| to 3f ; interorbital 2yV to 3i; teeth usually 2, 4-4, 2, 

 rarely 1, 4-4, 2 or 0, 4-4, 2. Body compressed, robust. Llead com- 

 pressed, broad. Snout convex, width f its length. Eye small in 

 adult, large in young, high. Mouth small. Maxillary to eye. Upper 

 jaw projecting. Mandible small, dentaries closely wedged together, 

 incurved, producing trilobed appearance. Interorbital broadly flat- 

 tened. Rakers 1 + 3 small rounded tubercles. Scales crowded anter- 

 iorly on trunk. L. 1. continuous in adult, midway along side, incom- 

 plete or absent in young. Dorsal origin midway between front pupil 

 margin and caudal base. Anal inserted just behind dorsal base. 

 Caudal emarginate. Pectoral f to ventral, latter inserted trifle before 

 dorsal origin, reaches vent. Color olivaceous above, below whitish. 

 Diffuse dusky blotch at caudal base, most distinct in young. Fins 

 otherwise plain. Iris whitish. Length If to 4|- inches. Many 

 examples: from the Delaware R. basin at Mendenhall, Black Horse 

 Run and first tributary below, Mill Run (Chester Co.): Susquehanna 

 R. basin at York Furnace (York Co.); Paradise, near Denver and Wit- 

 mer's Mills (Lancaster Co.); Emporium (Cameron Co.): Allegheny 

 R. basin at Cole Grove (McKean Co.). 



This peculiar and strikingly characterized species occurs in all our 

 river basins, but seems to be most abundant in the Susquehanna. It 



