FISHES 



33 



A. calva L. Dogfish; bowiin (Fig. i6}. Length 450 to 600 mm.; 

 head 3.7; depth 4 to 4.5; color dark olive or blackish, with traces of 

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

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



Fig. 15. — Lepisosteus iristcechus (Jordan ijf Evermann) . 



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 cr' 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; 8 orders in the fresh 

 waters of the United States. 



Key to these Orders of Teleostei 



ai Ventral fins abdominal (Fig. 3) in position (in the eels absent) ; 

 no spinous rays in the fins (except in the catfish) . 

 bi Head not scaly. 



Ci Body covered with scales (in the eels imbedded and 



hidden). 

 3 



