^LUBICHTHYS. 115 



B. Posterior nostril with a barbel; barbels 8; ventral fins witb 8 or 9 rays. 

 Preemaxillary band of teeth of equal breadth throughout, or sometimes very 



slightly produced backwards at the sides ; lower jaw not projecting . . 7. Amiukus. 

 Prsemaxillary band of teeth with a well-developed posterior extension on each 



side J lower jaw somewhat projecting 8. Leptops. 



1. ^LUPJCHTPIYS, Baird & Girard, 1854. 

 JElurichthys, Giinth. Cat. Fish. v. p. 177 (1861)- 

 Felichthys (Swainson), Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 116. 



Body elongate. Mouth terminal or subterminal; jaws with villiform teeth in bands ; vomerine and palatine 

 teeth ; nostrils close together, the posterior with a flap ; a pair of maxillary and a pair of mental barbels. 

 Parieto-oocipital with a process which extends posteriorly to the small basal shield of the dorsal spine. 

 Dorsal fin with a strong spine and 7 branched rays ; adipose fin short ; anal moderate or rather long ; 

 Ventral fins 6-rayed ; caudal deeply forked. 



Eight species from the Coasts and Rivers of America. 



It seems most useful to deal here with the whole genus and not to omit the two 

 species {A. hahiensis and A. hagre) which are not known to range so far north as 

 Central America, but which may do so. 



Syno])sis of the Species. 



I. Occipital process of nearly equal breadth throughout, with convex lateral edges * ; spine of 



dorsal fin not bearing a filament ; about 14 gill-rakers on the lower part of the anterior 

 arch. 



A. Vomerine patches of teeth separate, nearly equal in length and breadth 



to the palatine patches; occipital process not broader than long; 



anal of 26 or 27 rays . 1. panamensis. 



B. Vomerine patches of teeth united, considerably broader than the palatine patches ; occipital 



process broader than long. 



Breadth of occipital process | or nearly | the length of head ; anal of 28 rays, 

 produced anteriorly, the longest ray, when laid back, reaching beyond 

 the end of the base of the fin 2. scutatus. 



Breadth of occipital process -J- the length of head; anal of 29 or 30 rays, the 



longest, when laid hack, not reaching the end of the base of the fin . . 3. isthmensis. 



II. Occipital process narrowed posteriorly, with concave or straight lateral edges ; spine of dorsal 

 fin bearing a long filamentous ray ; not more than 10 gill-rakers on the lower part of the 

 anterior arch. 



A. Distance from tip of snout to origin of dorsal nearly -J- the length of the fish (to l)asc 

 of caudal). 

 1. Pectoral spine 4 to | as long as the head. 

 Anal of 22 to 24 rays, the longest nearly as long as or shorter than the base 



of the fin ; dorsal filament not reaching the adipose fin 4. marinus. 



* la the species of this section the occipital process has the appearance of a separate nuchal shield. 



Q2 



