ANGUILLA. 401 



A P O D E S. 

 ANGUILLID^E. 



Maxillary bones present, separated on the median line by the ethmo-vomer ; palato- 

 pterygoid bone present, connected with the hyomandibular and quadrate ; gill-openings 

 separate, opening into the pharynx by wide slits ; tongue present ; vent far removed 

 from the head. 



The Eels are spread over all the seas of the temperate and tropical zones, often 

 descending to great depths, a few entering fresh waters ; one of these is represented 

 in the Nile. 



1. ANGUILLA. 



Shaw, Gen. Zool. iv. p. 15 (1804) ; Giinther, Cat. Fish. viii. p. 23 (1870). 



Body much elongate, serpentiform, with minute scales imbedded in the skin, arranged 

 in small groups placed obliquely at right angles to one another. Pectoral fins well 

 developed ; dorsal and anal fins very long, united at the end of the tail, the former 

 originating at a great distance from the occiput. Mouth large, with more or less 

 developed lips; jaws and palate with bands of small pointed teeth; nostrils widely 

 separated from each other, the anterior tubular and at the tip of the snout, the posterior 

 slit-like and close to the eye. Gill-openings small, crescentic, close to the base of the 

 pectoral fins. 



The true Eels breed in the sea and undergo very marked metamorphoses ; the larvae, 

 hyaline and compressed, have long been known as problematic fishes under the name 

 of Leptocephalus *. 



* A nominal genus including larval forms of various xlpodes. The larva of the Common Eel has been 

 described under the name of Leptocephalus brevirostris, Kaup. 



3p 



