THE FISHES OF NEW. JERSEY. 125 
thorax ocellatus of Agassiz was based on a Brazilian fish, a form 
which I have not seen, but which differs according to the original 
figure in the more sparse and enlarged dark blotches. 
Order EVENTOGNATHI. 
The Carp Like Fishes. 
This group includes the majority of fresh-water fishes of the 
world. 
Key to the families. 
a. Pharyneal teeth few; margin of upper jaw formed by premaxillariés 
alone. CYPRINID A} 
aa. Pharyngeal teeth many, pectinate; maxillaries forming part of margin 
of upper jaw. CATOSTOMATIDAS 
Family CYPRINID. 
The Carps. 
Body of various form. Belly usually rounded, rarely com- 
pressed and never serrated. Margin of upper jaw formed by 
premaxillaries alone. Barbels 2 or 4, absent in most of our 
genera and not large in any. Gill-openings moderate, membranes 
broadly joined to isthmus. Gills 4, slit behind fourth. Pseudo- 
branchie usually present. Branchiostegals 3. Lower pharyn- 
geal bones well developed, falciform, nearly parallel with gill- 
arches, each provided with 1 to 3 series of teeth in small number, 
4 to 7 in main row and less number in others if more are present. 
Air-vessel usually large, commonly divided into an anterior and 
a posterior lobe, not inclosed in a bony capsule, and rarely 
wanting. Stomach without appendages, appearing as a simple 
enlargement of the intestines. Head naked. Body mostly scaly. 
Dorsal fin short in our species, elongate in those of the Old 
World. Ventral fins abdominal. 
Fresh-water fishes of moderate or small size of the Old 
World and North America. Where found they are excessively 
abundant both in species and individuals and from their great 
uniformity in size, form and coloration constituting one of the 
