Jordan and Evermann. Fishes of North America. 631 



regularly arranged. Lateral line wanting or represented by a few imper- 

 fect pores. Head scaly, at least above. Mouth terminal, small, the lower 

 jaw usually projecting; margin of the upper jaw formed by the premax- 

 illaries only ; premaxillaries strong, extremely protractile. Teeth incisor- 

 like or villiform, sometimes present on the vomer,but usually in the jaws 

 only ; lower pharyngeals separate, with cardiform or rarely molar teeth ; 

 third upper pharyngeal enlarged, the fourth wanting or united to the 

 third. Gill membranes somewhat connected, free from isthmus; gill 

 rakers very short, thick. Branchiostegals 4 to 6. Pseudobrauchise none. 

 Dorsal fin single, inserted posteriorly, of soft rays only, rarely with a sin- 

 gle spine or a rudimentary spinous dorsal ; caudal fin not forked ; ventral 

 fins abdominal, rarely wanting ; pectoral fins inserted low ; no adipose fin. 

 Stomach siphonal, without pyloric appendages. Air bladder simple, often 

 wanting. Basis cranii simple (fide Cope). Sexes usually unlike, the fins 

 being largest in the males, but in some species the females are much larger 

 in size. Many of the species are ovoviviparous, the young well developed 

 at time of birth. In these species the sexes are very unlike, the anal fin 

 of the male being developed as an intromittent organ. Fresh- water fishes 

 of Southern Europe, Asia, Africa, and America, some of them occurring 

 in bays and arms of the sea. They are mostly of small size, and the spe- 

 cies are very difficult of determination. Genera 30 ; species about 180. 

 (Pceciliidw, Bonaparte Nuovi Ann. Sci, Nat., n, 132, 1838.) 



We begin the discussion of this group with the largest genus, which 

 seems at the same time to be the most primitive and the least specialized. 



a. Intestinal canal comparatively short, little convoluted; teeth little movable; bones of the 

 dentary firmly connected; the lower jaw strong and usually projecting beyond upper; 

 species chiefly carnivorous. 



b. Anal fin of the male similar to that of the female and not modified into an intromit- 

 tent organ. Species oviparous. 



c. Teeth all pointed, none of them compressed or bicuspid or tricuspid. 

 FUNDULIN.E : 



<?. Ventral fins well developed; pharyngeal bones and teeth not enlarged. 

 c. Teeth in villiform bands or at least in more than one series. 



/. Air bladder well developed (in all species examined); no caudal ocellus. 

 (j. Gill openings not restricted above, the opercular angle free from 

 shoulder girdle; body oblong; dorsal various in size and inser- 

 tion. FUNDULTJS, 300. 

 gg. Gill openings restricted, the opercle from upper root of pectoral 

 upward being adnateto shoulder girdle; body short and deep. 



ADINIA, 301. 



ff. Air bladder wanting; a black ocellus at root of caudal at least in 



males. Kivutus, 302. 



ee. Teeth arranged in a single series; dorsal inserted in advance of anal; mouth 



oblique. 



j. Dorsal and anal fins short, each of 9 to 13 rays. LUCANIA, 303. 



jj. Dorsal and anal fins very long, each of more than 20 rays. 



GIRA.RDINICHTIIYS, 304- 

 ORESTIINJE : 



del. Ventral fins wanting; body oblong. 



t. Pharyngeal bones both above and below greatly enlarged, bearing coarse 

 molar teeth; scales normal, regularly imbricated, none of them ridged. 



EMPETKICHTHYS, 305. 

 CVPRINODONTINJE : 

 cc. Teeth incisor-like, notched, bicuspid or triouspid. 



j. Ventral fins well developed (occasionally lost through atrophy); gill openings 

 restricted; the opercle aduate above to the shoulder girdle. 



