254 FISHES. 



contracted, with the lower jaw projecting; eyes very 

 large 3|j- in head; ventral fins long, reaching about to 

 vent; D. VI 15; A. 11; L, 21. Lake Michigan in 

 deep water. 



2. POTAMOCOTTUS, Gill. BLOBS. 



1. P. meridionalis, (Grd.) Gill. CAVE BULL-HEAD. 

 GOBLIN. BLOB. MUFFLE - JAWS. Head 3^ in length; 

 depth 5; width of head 3; P. reaching beyond begin- 

 ning of soft dorsal, to anal; preopercle with a stout erect 

 spine and two smaller ones below; mouth wide; palatine 

 teeth unusually strong; lateral line very distinct, chain- 

 like, sometimes vanishing behind, and sometimes not. 

 Grayish, mottled, three cross blotches on back; D. VI to 

 VIII-16; A. 12 or 13; V. 1, 4. N. C. to Ala., Tenn., 

 and Ind., abounding in many of the streams issuing from 

 the caves in the limestone region; the largest species 

 of the genus, reaching a length of 6 inches. (C. merid- 

 ionalis, Grd. P. carolinoe, Gill., P. zopherm, Jor.) 



2. P. richardsonii, (Ag.) Gill. LAKE SUPERIOR MIL- 

 LER'S THUMB. Pectorals shorter than head, scarcely 

 reaching second dorsal; depth 6 in total length; head 

 4J; eye 5^- in head; vent near the middle of total length; 

 D. VIII -18; A. 14. L. Superior; one of the largest 

 species. 



3. P. bairdii, (Girard) Gill. BAIRD'S BULL -HEAD. 

 Peotorals long, reaching beyond beginning of anal; 

 depth 6 to 6^- in total length; spinous dorsal very low, 

 with a black bar; head 4^ in length; eye 4 in head; 

 D. VI to VII 16 ; A. 13. Ohio, etc. 



4. P. alvordii, (Grd.) Gill. Similar to the preceding but 

 stouter, with the pectorals rather shorter, and the dorsal 

 spines higher, 7 or 8 in number; color dark, variegated; 



