xxii HAPLOMI 605 



ethmo-vomer ; palato-pterygoid bone separated from hyomandi- 

 bular arch ; branchial openings into the pharynx narrow slits ; 

 no tongue, 



The body is naked, pectoral fins are usually absent, and the 

 gill-cleft is a small round opening. The opercular bones are 

 much reduced in size, and the pectoral arch may be totally absent. 



Voracious marine Fishes, inhabiting tropical and sub-tropical 

 waters, being especially abundant about coral reefs. Some 120 

 species are known, many reaching a very large size, and being 

 also remarkable for their variegated coloration. The genera are 

 mostly founded on the dentition, which shows much diversity ; 

 the following are the principal : Myroconger, Enchelycore, 

 Jft'.racna, Tkyrsoidea, Lycodontis, Pythonichthys, Echidna, Ckan- 

 nomuraena. The Muraena of the ancient Eomans, Muraena 

 Helena, of the Mediterranean, Eastern Atlantic, and neighbouring 

 parts of the Indian Ocean, occurring exceptionally as far north 

 as the English coast, grows to 4 feet, and its flesh was more 

 esteemed than that of any other Fish, large numbers being reared 

 in specially constructed reservoirs near the sea, and fed on the 

 corpses of slaves. Channomuraena vittata, from the coast of Cuba, 

 is known to attain a length of 8 feet, and Thyrsoidea macrura, 

 from the Indian Ocean and the Malay Archipelago, to upwards 

 of 10 feet. 



Sub-Order 5. Haplomi. 



Air-bladder, if present, communicating with the digestive 

 tract by a duct. Opercle well developed. Pectoral arch sus- 

 pended from the skull ; no mesocoracoid arch. Fins usually 

 without, rarely with a few spines ; ventrals abdominal, if present. 

 Anterior vertebrae distinct, without Weberian ossicles. 



The absence of the mesocoracoid arch distinguishes the 

 Haplomi from the Malacopterygii, with which they are united 

 by various authors. They lead to the Percesoces through the 

 Cyprinodontids, and to the Lower Acanthopterygians, such as 

 the Berycidae, through the Scopelids, Stephanoberycids, and 

 Percopsids, as is evidenced by the structure of the mouth and 

 the forward position, in some of the genera, of the ventral fins, 

 which, however, are never attached to the pectoral girdle. Most 

 of the forms which are here included inhabit either fresh water 

 or the deep sea. 



