LEPISOSTEID^. — XXII. 35 



and vent. D, 42, A. 27. Changes greatly with age, the young 

 with sharp snout and very rough shields, and the spines strongly 

 hooked ; the adult with blunt snout and small smooth shields, most 

 of them finally lost. L. 6 feet. Miss. Valley, Great Lakes, and 

 N., abundant, ascending rivers in spring, but not entering the sea. 

 (Lat., ruddy.) 



ce, Last dorsal shield very small, less thaa half length of next the last ; 



dorsal shields 10 to 12. 



43. A. brevirostrum Le Sueur. Snout short, bluntish, much 



shorter than rest of head. Dorsal shields 11 ; lateral, 30 ; ventral, 9 ; 



one shield between anal and vent. D. 43, A. 24. N. Y. to Fla., 



scarce. (Lat. brevis, short; rostrum, snout.) 



Order IX. GINGIiYMODI, 



This order, defined on page 25, contains but one family among 

 recent fishes, although it has many allies among extinct forms; . 

 (yiyyXu/ioy, hinge ; el&os, tooth.) 



Family XXn. LBPISOSTBID^. (The Gar-pishes.) 



Body subcylindical, covered with rhombic enamelled " ganoid " 

 scales, imbricated in oblique series which run downward and back- 

 ward. Jaws both elongate, the upper always projecting ; pre- 

 maxillary forming most of upper jaw, the maxillary transversely 

 divided into several pieces ; lower jaw formed much as in rep- 

 tiles; both jaws with an outer series of small teeth followed by one 

 or two series of larger teeth of peculiar structure ; close-set, rasp- 

 like teeth on jaws, vomer, and palatines ; tongue toothless, broad, 

 emarginate ; external bones of head very hard, rugose. Eyes 

 moderate ; nostrils near end of snout ; pseudobranchiK present, 

 besides an opercular gill; B. 3; no spiracles; air-bladder cellular, 

 joined by a glottis to the oesophagus, resembling the lungs of rep- 

 tiles, and used in respiration. Fins with fulcra ; D. short, nearly 

 opposite A. ; tail heterocercal, produced as a filament in young ; 

 vertebrae with ball and socket joint, as in reptiles ; pyloric coeca 

 many. One genus now living, with 3 or 4 species. Singular fishes, 

 inhabiting the lakes and larger rivers of Eastern North America. 

 The species are extremely variable in coloration, length of snout, 

 proportions, etc., a fact which has given rise to a multitude of use- 

 less specific names. 



32. LEPISOSTEUS Laclpede. 

 (Xfm'j, scale; dariov, bone; more correctly written Lepidosteus, 



but the above is the original word.) 

 it. Beak long and slender, the snout more than twice length of rest of head. 



44. L. osseuB (L.). Common Gar-Pike. Long-nosed Gab. 

 Bill-fish. Olivaceous; vertical fins and posterior parts with 



