FISHES 



33 



dark reticulate markings on the sides; paler below; male with a round 

 black spot edged with orange at the base of the tail; dorsal fin with 

 48 rays; anal 10 to 12; scales 67: eastern and central States, southward 

 to Florida and Texas; northward to Vermont and Minnesota; common; 

 in lakes and sluggish waters; not used for food. The eggs are deposited 

 in a nest formed by the male in a gravelly or sandy bottom, who then 

 guards them and also the young after they are hatched. 



Fig. 16. — Amia calva (Jordan c-' Evermann) . 



Series 2. Teleostei. — The bony fishes. Fishes with a bony 

 skeleton and with usually a homocercal, never a heterocercal, tail; 

 scales cycloid or ctenoid, or wanting; opercles present; air bladder 

 usually present, but without cells and usually with a more or less 

 rudimentary pneumatic duct, or none; without spiral valve; arterial 

 bulb with a single pair of valves: many orders; 17 orders in the fresh 

 waters of the United States. 



Key to These Orders of Teleostei 



ai Ventral fins, if present, abdominal (Fig. 3) in posi- 

 tion; in eels absent, 

 bi Head without scales. 

 Ci Fins without spines, 

 di Ventral fins present. 



ei Branchiostegals 4 or more; lake white- 

 fish and herring, salmon, trout i. Isospondyli (p. 34). 



e2 Branchiostegals 3. 



fi Pseudobranchiae present (rarely ab- 

 sent); suckers, carp, dace, minnows 3. Eventognathi (p. 50). 

 U Pseudobranchia; absent (but one 



species in United States) 4. Heterognathi (p. 85). 



di Ventral fins absent; eels 2. Enchelycephall (p. 50). 



Ci Fins with spines. 



di Barbels present; body scaleless; catfish. . . 5. Nematognathi (p. 85). 

 do No barbels present. 



ei Body covered with scales; trout-perch. . 8. Salmopercce (p. loi). 

 e2 Body without scales, and either naked 



or with bony plates; sticklebacks. ... 11. Thoracostei (p. 102). 



