Jorda n and Everman n . Fishes of North A merica . 2093 



They arc numerous in the warm seas, and those of sufficient size are valued 

 as food. Genera about 12; species 150. The North American species 

 belong to 2 subfamilies very different one from the other. The soles are 

 naturally divisible into 3 subfamilies, each quite distinct from the others, 

 and possibly independently descended or degraded from normal Pleuron- 

 ectidcv. The A ch win at, or American soles, are apparently allied to the Pset- 

 tiitu', and as in the latter, the ventral nn of the eyed side extends along the 

 ridge of the abdomen. The Soleincv, or European soles, show in the inser- 

 tion of ventral and in other respects a strong resemblance to the Pleiiro- 

 nectiiui'. The more aberrant Cynoylossince, or tongue fishes, are perhaps 

 degraded Solemn, but the eyes are sinistral, as in the Psettincv. In the 

 Soleinw and Acliirlnce the eyes are dextral, as in the Pleuronectince. 



I. Soles witli the eyes on the right side and separated by a distinct bony ridge; tae ven- 



tral with long base confluent with the anal. Body oblong or ovate, with the color 



on the right side ; eyes moderate or small, the upper eye usually more or less in 



advance of the lower; mouth small, more or less twisted toward the blind side ; 



teeth little developed, in villiform bands ; edge of opercle adnate, usually con- 



cealed by the scales ; gill openings more or less narrowed, the gill membranes 



adnate to the shoulder girdle above ; blind side of head usually with fringes ; pec- 



toral fins small, sometimes wanting; ventral fins developed, one or both of them 



sometimes obsolete ; scales usually ctenoid, rarely wanting ; lateral line straight, 



usually single ; right ventral with extended base, confluent with the anal fin. 



a. Gill openings of moderate extent, confluent below; vertical fins well separated; 



body ovate in" outline, the depth nearly the length ; pectoral fins rudi- 



mentary or wanting ; lateral line straight ; scales well developed, ctenoid, 



those on the head more or less enlarged, those of the blind side of the head 



with fringes ; vertebrae about 28. ACHIRUS, 1054. 



aa. Gill openings very small, separate, each reduced to a small slit below angle of 



opercle ; right ventral beginning at the chin ; pectoral fins minute or want- 



ing; lateral line straight; snout dilated, the dorsal beginning upon it. 



b. Scales present, ctenoid ; caudal somewhat confluent with dorsal. 



c. Left ventral rudimentary, with 2 rays. APIONICHTHYS, 1055. 



bb. Scales none ; caudal free from dorsal and anal. GYMNACHIRUS, 1056. 



CYNOGLOSSIN^: : 



II. Soles Avith the eyes on the left side, not separated by a bony ridge. Body elongate, 



more or less lanceolate in outline, with the color on the left side; eyes small, 

 very close together, with no distinct interorbital ridge between them; mouth 

 small, twisted toward the blind side; teeth little developed, in villiform bands; 

 gill openings narrow, the gill membranes adnate to the shoulder girdle above, 

 joined together and free from the isthmus below; pectoral fins wanting (in the 

 adult); ventral fins small, that of the blind side often wanting ; vertical fins 

 more or less confluent; scales ctenoid: lateral lines sometimes wanting, some- 

 times duplicated. 



d. Ventral fin of eyed side only present, free from the anal ; no pectoral fins ; no 

 lateral line; head without fringes. SYMPHURUS, 1057. 



1054. ACHIRUS, Lacepede. 



(AMERICAN SOLES.) 



Achirus, LACEPEDE, Hist. Nat. Poiss., iv, 659, 1803 (fasciatus, etc.). 

 Achirus, CUVIER, Regne Animal, Ed. 2, II, 343, 1829 (restriction to fasciatus, etc.). 

 Trinectes, RAFINESQUE, Atlantic Journal and Friend of Knowledge, i, 1832 (scabra). 

 Grammichthys, KAUP, Archiv fur Naturgsch. 1858, 94 (lineatus; fasciatus) ; Achirus being 

 restricted to Pardachirus barbatus, etc. 



