328 REPORT' OF COMMISSIONER OF FISH AND FISHERIES. [104] 



Lately the relations of these forms have been made the subject of 

 careful study by Dr. Carlo Emery, Dr. Luigi Facciola, and others of 

 the Italian naturalists, and no doubt remains that the "Bibroniidce " are 

 larval flounders and soles. 



For the sake of completeness, we give the following analysis of the 

 nominal genera and the synonymy of the species : 



ANALYSIS OF THE NOMINAL GENERA OF BIBRONIiE OR LARVAL FLOUNDERS AND SOLES. 



a. Eyes wholly sinistral ; mouth toothless, shaped as in the soles; upper jaw hook- 

 shaped ; head very small ; caudal fin suhsessile, free from the dorsal and 

 anal; scales small, caducous, cycloid; eyes small; pectoral fins both 

 present, the right pectoral small ; ventral fins both present, free from anal ; 

 dorsal fin of long, simple rays, their tips much exserted ; body moderately 

 elongate ; the depth 3 in length ; dorsal rays 100 ; anal rays 80. P. 12-4. 



Delothyris, A. 



aa. Eyes partly sinistral, the one on the left side, the other on the vertex (in the 

 act of transition) ; form pleuronectoid Coccolus, B. 



aaa. Eyes, one on either side of the head ; strictly symmetrical (or with the right eye 

 somewhat higher than the other), and with a notch before it, between the 

 cranium and the dorsal fin. 

 o. Vertical fins scarcely or not confluent ; left ventral largest, on abdominal ridge, 

 e. Body excessively compressed, broadly ovate, its depth If in its length; both 

 profiles very convex ; the snout not forming an angle ; no scales; none of 

 the dorsal rays prolonged ; ventral fin single (Facciola) ; pectoral fins short, 

 rounded, with fleshy base and fringe-like rays ; D. 85 ; A. 65. Jaws equal, 



with small, acute teeth Peloria, C. 



cc. Body more elongate; scales present or absent; pectorals adipose, with fringe- 

 like rays. 



d. Ventral fin single ; first four rays of the dorsal well separated and with 

 much exserted tips; dorsal and anal slightly joined to caudal; depth about 

 4£ in length ;* D. 4, 106 ; A. 100. (Emery) ? Charybdia, D. 



dd. Ventral fins both present, the left ventral with more prolonged base ; 

 dorsal with only the first ray (if any) prolonged; dorsal and anal free from 



caudal ; depth 2£ to 2 in length ( Facciola) Charybdia, D. 



ob. Vertical fins fully confluent ; form lanceolate. 



e. Body linguiform, the depth 6 in length; no teeth; snout obtuse; eyes 

 minute; ventral fins two; four or five of the dorsal rays produced; pec- 

 torals pedunculate. D. 90; A. 80 Bibronia, E. 



ee. Body plagusiiform ; perfectly transparent Bascanius, F. 



Synonymy of genera of larval Pleuronectidw or Bibronkc. 



Bibronia Cocco, "Intorno ad alcuni Pesci del mare di Messina. Lettera al Sig. 

 Augusto Krohn da Livonia. In Giornale del Gabinetto & Lettere di Mes- 

 sina. Aun. iii, torn, v, fasc. xxv. Genuaio e febbraio 1844, pag. 21-30, tav. 

 2" (fide Facciola) (ligulata). 



Peloria Cocco, 1. c. (hceckeli). 



Coccolus (Bonaparte) Cocco, 1. c. (anneclens). 



Bascanius Sckiodte, Naturhist. Tidsskr., v, 209, 1867 (tcedifer). 



Thyris Goode, Proc. U. S. Nat. Mus., 1880, 344 (jpellucidus ; name preoccupied). 



Delothyris Goode, Proc. U. S. Nat. Mus., 1883, 110 (pellucidus). 



Charybdia Facciola, Naturalista Siciliano, iv, 265, 1885 (riippelli). 



