2694 DuUctin //, United States National nruscum. 



Monochinis, Kaup, Archiv fur Naturgsch. 1858, 94 {mamlipinnis) ; not of Rafinesque. 



1814, a genus of Soleince. 

 ? Aseraggodes. Kaup, Archiv fur Naturgscli. 1858, 103 (guttidafa). 

 Baiostoma, Bean, Proc. U. S. Nat. Mus. 1882, 413 (hrachiale). 

 Bceostoma, Jordan & Gilbert, Synopsis, 965, 1883 ; amended ortbograi>liy. 



Eyes and color on the riglit side. Body oblong, bluntly rounded ante- 

 riorly. Head small; eyes small, close together, the upper eye in advanct; 

 of the lower, the two separated by a bony ridge; mouth small, somewhiit 

 turned toward the colored side; nasal llajjs present, the nostril of the 

 blind side fringed ; lii) of the colored side fringed ; teeth very small, on blind 

 side only; gill openings rather narrow, but confluent below, not reduced 

 to a slit; the branchiostegal region scaled. Head closely scaled every- 

 where, the scales on the colored side similar to those on the body, those of 

 the nape and chin much enlarged ; scales on the Idiud side anteriorly with 

 their pectinations more or less produced, forming cirri; scales of both 

 sides extremely rough, extending on the lins. Lateral line straight, sim- 

 ple; edge of preoperele covered by the scales. Dorsal beginning on the 

 snout, low in front and thickly scaled, its rays divided; anal tin similar, 

 without spine; caudal tin free, convex; caudal peduncle very short and 

 deep ; pectoral tin of left side wanting, that of right side small or obso- 

 lete; ventral rays 3 or 4, the ventral fin of the colored side long, eouaected 

 with the anal by a membrane. This strongly marked genus contains 

 numerous s^jecies, all very closely related, and nearly all American. It has 

 been united by Dr. Giinther with Solea, but for no good reason, as the 

 number of vertebrse is very much fewer than in the European soles, and 

 the right ventral fin is decurrent along the abdomen and united with the 

 anal in the American soles, while it is short and wholly free in all the 

 European forms. The 2 groups belong in fact to distinct subfamilies. It 

 is also worth noticing that the name JcJiii-iis is prior in date to that of 

 Solea. The species with rudimentary pectoral fins have been set apart by 

 Dr. Beau to form the genus liaiostoma, but the ^ery slight development of 

 these organs in some of the species and the evidently very close relation- 

 ship of them all lead us to regard Baiostoma as a subgenus only. If we 

 follow Kaup in restricting the name Achints to the Asiatic group called 

 Pardachirns, the present genus would receive the name of Trinectcs. It 

 seems to ns, however, that both Laceprde and Cuvier regarded the species 

 called by ua fasciatus as the type of their genus Achirus. {ax^'Pi without 

 hands; without pectoral fins.) 



Baiostoma (^aios, small; aToixa, mouth): 

 a. Pectoral fins small, present at least on the right side. 



b. Pectoral fin present on both sides, that of the left side rudimentary, of a single 



ray ; that of the eyed side with about 3 rays. 



c. Dorsal rays 60 to 67; anal rays about 48; scales 80; depth ^ in length. 



Color brownish, irregularly spotted with darker, and with about 10 



black vertical lines crossing the lateral line. achirus, 3065. 



cc. Dorsal rays 53 to 57 ; scales 75 to 80; depth Ig in length; scales not very 



rough, those of colored side with scattered, hair-like appendages, 



some black, others pale. Color olivaceous; head, body, dorsal, and 



anal fins covered with a network of dark lines; traces of about 8 



dark cross streaks sometimes present. insckiptu.s, 3066. 



