85. PERCID.E PERCA. 523 



small, slightly oblique, maxillary reaching front of eye. Eye small, 4 

 in head, Cheeks and opercles with large scales. Opercular spine well 

 developed. Scales large, the tubes of the lateral line developed on two 

 of them; dorsals well separated. Anal spines slender, high; pectorals 

 and veutrals reaching about to vent. Olive, speckled with brown; ten 

 brownish spots along the sides; black streaks downward and forward 

 from eye; dorsal fins mottled. Head 4; depth 4. D. VIII, 11 j A. 

 II, 6. Lat. 1. 36. L. 1 inches. Alabama and Mississippi. 



(Hay, Proc. U. S. Nat. Mus. 1880, 498.) 



825. M. piiBBCtoaHata Putnam. Least Darter. 



Body rather short and deep, somewhat compressed, the back arched. 

 Caudal peduncle rather long. Head moderate. The snout somewhat 

 decurved. The mouth moderate, terminal, oblique. Cheeks naked. 

 Opercles somewhat scaly.. Opercular spine very small. Neck and chest 

 naked. No trace of lateral line. The usual series of tubes along the tem- 

 poral region. Scales quite large, strongly ctenoid. Vertical fins short. 

 Anal spines strong, the first usually the largest. Coloration olivaceous, 

 the sides closely speckled and with vague bars and zigzag markings ; sec- 

 ond dorsal and caudal barred ; dark streaks radiating from eye ; a dark 

 humeral spot. Head 3; depth 4. D. VI- VII, 10; A. II, G; Lat, 1. 

 34. L. 1 inches. Smallest of the darters, and one of the smallest of 

 fishes, abounding in the clear streams of the Northwestern States. 



(Putnam, Bull. Mus. Comp. Zool. i, 1863, 4; Jordan, Man. Vert. 229.) 



268. PEKCA Linnaeus. 



Perch. 

 (Arterli: Linnaeus, Systema Naturae : type Perca fluviatilis L.) 



Body oblong, somewhat compressed, the back elevated. Cheeks 

 scaly; opercles mostly naked; the operculum armed with a single 

 spine. Preopercle and shoulder girdle serrated. Mouth moderate, 

 terminal ; premaxillaries protractile ; teeth in villiform bands on jaws, 

 vomer, and palatines ; no canine teeth. Branchiostegals 7. Gill-mem- 

 branes separate; pseudobranchise small, but perfect; no anal papilla. 

 Scales rather small, strongly ctenoid. Lateral line complete. Dorsal 

 fins entirely separate, the first of 12-15 spines; anal fin with two slender 

 spines; caudal emarginate; air-bladder present. Pyloric cceca3; ver- 

 tebrae (P. fluviatilis) 21+20. Fresh waters of northern regions; three 

 species now known: P.flumatllis in Europe, P. sclirencld in Asia, and 

 P. americana. This genus has long been considered the type of the 



