28i8 



THE BONY FISHES AND GANOIDS 



stomach has a blind appendage; the vent is generally situated far back, but may be 

 near the pectoral fins; and the ovaries have no ducts. Externally the skin may be 

 either completely naked, or may contain rudimental scales. In the skeleton the 

 pectoral arch is unconnected with the skull, and attached to one of the earlier ver- 

 tebrae. Eels are found in the fresh waters and seas of the greater part of the tem- 

 perate and tropical regions; some living at abyssal depths in the ocean. The young 

 of some forms are pelagic for a portion of their existence; and it is believed that a 

 large number of the so-called Leptocephali (seep. 2690), or glass eels, are abnor- 

 mal larvae of this family. Geologically the family is a comparatively ancient one, 

 true eels having been discovered in the Chalk of the Lebanon, as well as in the 



Muraenas 



MEDITERRANEAN MUR^NA. 

 (One-fifth natural size.) 



Tertiaries of Europe. Congers referred to the existing genus Ophichthys have been 

 described from the middle Eocene of Monte Bolca, and there is also an extinct genus 

 from the latter deposits, and a second from the London Clay. 



The muraenas are large marine eels remarkable for their bright 

 spotted or mottled coloration, and taking their name from the species 

 here figured (Mur&na helena) which was so called by the ancient Romans. Belong- 

 ing to a small section of the family characterized by the gill openings into the 

 pharynx being in the form of narrow slits, they are specially distinguished by the 

 median fins being well developed, and the total absence of pectorals. The skin is 

 scaleless; the mouth is well furnished with teeth; and there are two nostrils on each 

 side of the muzzle, the front pair being tubular; while the hinder ones may be either 

 tube-like or mere flat openings. The muraenas, of which there are more than eighty 



