92 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



50.— L.ITHOI.EPIS Rafinesque. 



Alligator Gars. 



CAtractosteus Rafiuesque, 1820.) 



(Rafinesque, Amer. Month. Mag. iii, 447, 1818: tjpe Litholepis adamantinus Raf.) 



This genus is scarcely distinct from Lepidosteus, differing only in the 

 presence of a second series of large teeth in the upper jaw, along the 

 outer margin of the palatine bones, at their junction with the premaxil- 

 laries. Probably but one species, in the warmer parts of the United 

 States, and southward to Cuba and Central America. {XiOocj stone j 

 ^e-k, scale.) 



§2. li. tB'B sice elms (Blocli & Schneider) Jordan & Gilbert. — Alligator Gar. 



Color greenish, paler below, the adult usually not sjiotted. Snout 

 usually not quite so long as the rest of the head, its least width con- 

 tained 3 J times in its length. Head 3^ in length. D. 8 ; A. 8 ; V. ; 

 Lat. 1. 60. Scales in an oblique series from the ventrals to middle of 

 back 18-20. L. 8-10 feet. Eivers of the Southern States, Cuba, Mex- 

 ico, and Central America ; reaching a great size. 



(Jf Esox viridis Gmelin ed. Linn6, i, 1380: Esox iristoeclms Schneider ed. Bloch, 395: 

 Lepuostcus spatula Lacep. v, 333: Lepisosteus or Airactosteus ferox Rafinesque, Ichth. 

 Oh. 73: Lepidosteus manjuari Poey, M^m. Cuba, 1,273: f Airactosteus tropicus Gill, Proc. 

 Acad. Nat. Sci. Phila. 18(33, 172: Lepidosteus viridis Giiuther, viii, 329.) 



Oedee J.-HALECOMORFHI. 



{The Amias.) 



Parietals in contact. Pterotic, basis cranii, and anterior veftebrae 

 simjjle. Mandible with opercular and coronoid. Maxillary not trans- 

 versely segmented, bordering the mouth. Third superior pharyngeal 

 lying on enlarged fourth. Upper basihyal wanting. Vertebrae amjjhi- 

 ccelian. Pectoral fins with mesoi^terygium and eight other elements. 



This order includes only the family of Amiidce. (Ijatin lialecomorphus, 

 formed like a shad; in allusion to the resemblance between this group of 

 Ganoids and the Isospondyli.) 



Family XXVIII.— AMIID^. 



(The Mud-fishes.) 



Body oblong, compressed behind, terete anteriorly. Head subconical, 

 anteriorly bluntish, slightly depressed, its superficial bones corrugated 



