JULY, 1907. FISHES OF GREAT LAKES, NICARAGUA MEEK. 103 



aa. Gill openings, one on each side. 



c. Ventral fins present, abdominal, not composed of i spine and 



5 soft rays. 



d. Tail heterocercal ; scales rhomboidal, very hard, ganoid. 



Lepisosteidce 104 

 dd. Tail not heterocercal; scales absent or normal. 



e. Adipose fin on dorsal region present. 



f. Body without scales; mouth and chin with barbels; adipose 



fin long, longer than head. Silurida 105 



ff. Body with scales; mouth and chin without barbels; adipose 



fin very small. Characinidce 107 



ee. No adipose fin on dorsal region. 



g. Gular plate present between branches of lower jaw; scales 



very large. Elopida 1 1 1 



gg. No gular plate. 

 h. Ventral region compressed, armed with bony serrae. 



Dorosomida 112 



hh. Ventral region without bony serrae. 



i. Dorsal fin single, of soft rays only. Poeciliidce 112 



ii. Dorsal fins 2, the first of slender spines, the second of soft rays. 



AtherinidcB 114 

 cc. Ventral fins thoracic, each composed of i spine and 5 soft 



rays. 



j. Dorsal fin with more than 8 spines; anal spines 3 or more. 



k. Lateral line not interrupted ; nostril double on each side ; anal 



spines 3, the second very long and strong, longer than third. 



4 . Haemulidcz 116 



kk. Lateral line interrupted on each side; nostril single on each 



side; anal spines more than 3, the second shorter than the 



third. CichlidcB 117 



jj. Dorsal fin with less than 8 spines; anal spine single. Gobiidoe 131 



Family (w 

 Genus Carcharhiims Blainville. 



Sharks with a robust body, broad depressed head, inferior mouth, 

 strongly serrate teeth in both jaws and no spiracles; first dorsal fin 

 large, second small. 



Carcharhinus nicaraguensis (Gill & Bransford). TIGRONE. 



Eulamia nicaraguensis Gill & Bransford, Proc. Acad. Nat. Sci., 



