254 FISHES. 



contracted, with the lower jaw projecting; eyes very 

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

 vent; D. VI — 15; A. 11; L, 2i. Lake Michigan — in 

 deep water. 



2. POTAMOCOTTUS, Gill. Blobs. 



1. P. meridionalis, (Grd.) Gill. Cave Bull-Head. 

 Goblin. Blob. Mltffle - Jaws. Head 3^ in length; 

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

 ning of soft dorsal, to anal; j^reopercle 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 

 Vni-1(3; A. 12 or 13; V. 1, 1. 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 (S inches. {C. merid- 

 ionalis^ Grd. P. carolince^ Gill., P. zopherus^ Jor.) 



2. P. richardsonii, (Ag.) Gill. Lake Superiok Mil- 

 ler's Thumb. Pectorals shorter than head, scarcely 

 reaching second dorsal; depth (3 in total length; head 

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

 ]). VIII — 18; x\. 14. L. Superior; one of the largest 

 species. 



3. P. bairJii, (Girai-d) Gill. Baird's Bull -Head. 



Pectorals long, reaching beyond beginning of anal; 

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

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

 D. VI to VII— IG; 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 S in number; color dark, variegated; 



