2878 Bidletin ^7, United States National Museum. 



f. Mouth small, horizontal; posterior part of tongue and roof of 



mouth covered with coarse-paved teeth. 



LVII, Albulid.e, 410. 

 ff. Mouth large, the teeth all pointed, some of them canine, none 



paved or molar LVIII, Hiodontid.e, 412. 



ee. Teeth none; an accessory hranchial organ behind gill cavity. 



LIX, Chanid.e, 414. 

 (Id. Lateral line wanting ; no gular plate. 



g. Mouth small, inferior, toothless, the maxillary simple or nearly 



so; stomach gizzard-like LX, Dorosomatid,k, 415. 



gg. Mouth moderate, terminal, the maxillaiy of about 3 pieces; 



stomach not gizzard-like LXI, Clupeid^e, 417. 



ggg. Mouth subinferior, very large, below a tapering, pig-like snout; 



maxillary very long LXII, Engrai'lidid.e, 439. 



hh. Dorsal fin posterior, opposite anal ; deep-sea fishes, of loose 

 organization; mostly blackish in color; mouth small, 

 with small pointed teeth ; air bladder wanting. 



LXIII, Alepocephaliixe, 451. 

 BB. Dorsal fin single, preceded by free spines. 

 /(. Body scaleless, naked or with bony plates. 

 i. Ventral fins I, 1, the spine strong; snout moderate. 



XCVIII, Gasterosteid.e, 742. 

 ii. Ventral fins, I, 5, the spine slender; snout prolonged. 



XCIX, AULORIIYNCHID.E, 752. 



hh. Body scaly ; snout tubular C, Aulostomid^e, 754. 



BBB. Dorsal fin composed of free spines; ventrals with 1 or 2 spines 



each; body elongate LXXXVII, Notacanthid.e, 613. 



BBBB. Dorsal fins 2, the anterior of spines only, the posterior chiefly of 

 soft rays. 

 j. Pectoral fin with 5 to 8 lowermost rays detached and filamen- 

 tous CIX, POLYNEMID.E, 827. 



jj. Pectoral fin entire. 



A". Snout tubular, bearing the short jaws at the end; body com- 

 pressed CII, Macrorhamphosid.e, 758. 



hk. Snout not tubular. 

 /. Teeth strong, uneqiial ; lateral line present. 



CVIII, Sphyr.enid.e, 822. 

 II. Teeth small or wanting; lateral line obsolete. 



m. Dorsal spines 4, stout; anal spines 3 CVII, Mugilid.e, 808. 



mm. Dorsal spines 4 to 8, slender; anal spine single. 



CVl, AtherinidvE, 788. 

 BBBBB. Dorsal fin soft-rayed, followed by a series of detached finlets. 



XCVI, SCOMBKESOCID.E, 724. 



II.— VENTRAL FINS PRESENT, THORACIC OR SUBJUGULAR, THE NUMBER 

 OF RAYS DEFINITELY I, 5. 



A. Gill openings in front of the pectoral fins. 



B. Body more or less scaly or armed with bony plates. 



C. Ventral fins completely united; gill membranes joined to the 



isthmus; no lateral line CLXXXVIII, Gobiid.e, 2188. 



CC. Ventral fins separate. 



D. Suborbital with a bony stay, which extends across the cheek to 



or toward the preopercle; cheeks sometimes entirely 

 mailed. 



E. Pectoral fin with 3 lower ravs detached and free; head bonv. 



CLXXXIV, Tkiglid.e, 2147. 

 EE. Pectoral fin with 2 lower rays detached and free; body mailed. 



(JLXXXV, I'ERisxr.DiiD.E, 2177. 

 EEE. Pectoral fin entire. 



F. Slit behind fourth gill small or wanting. 



