TELE OS TS. 257 



fins present. Anguilla vulgaris, the common eel of Europe and America. 

 Conger vnlgaris, conger eel, almost cosmopolitan. The name Leptoceph- 

 alus was given to the young of both Anguilla and Conger. MUR/ENID^:, 

 gill slits small and rounded, pectorals lacking. Mjir&na, the murrys of 

 warmer seas. The Apodes are an old group, Anguilla dating from the 

 cretaceous. They have possibly descended from the Isospondyli. 



SUB-ORDER 3. LYOMERI. 



Deep sea physostomes with eel-shaped bodies, large heads, 5-6 simple 

 gill arches ; skull imperfectly ossified. In some features they appear de- 

 generate, in some primitive. But few specimens known. Eurypharynx, 

 Gastrostomus. 



SUB-ORDER 4. HAPLOMI. 



Physostomes with the head usually scaly, scales cycloid; shoulder 

 girdle attached to the cranium ; teeth present ; no adipose dorsal. UMBRID^E 

 (mud-minnows), teeth villiform; maxillaries forming the lateral part of the 

 jaw. Umbra. ESOCID^:, pikes, maxilla similar to the last ; teeth are card- 

 like and unequal. Esox, pickerel, pike, muskalunge. Esox dates from the 

 miocene, Ischyrhiza from the cretaceous of the United States. CYPRINO- 

 DONTiDyE, premaxilla forms the entire upper jaw; vent normal. Fundulus, 

 the mummichogs or killifishes, Anableps. Cyprinodon. Lebias from the 

 miocene. AMBLYOPSIDJE (Heteropygii) ; jaws as in cyprinodonts ; vent in 

 the branchial region ; species mostly cave inhabitants (American) and 

 have greatly degenerate eyes. Amblyopsis, Chologaster. The STRA 

 are extinct. Ciwolichthys, upper cretaceous. 



ORDER III. SYNENTOGNATHI. 



Large physoclistous bladder ; fins without spines ; lower 

 pharyngeals united into a single bone ; shoulder girdle con- 

 nected to cranium ; a row of keeled scales on the belly ; marine. 

 These forms are allied to the percesoces and the spine-finned 

 fishes. 



ExocGETiD,E or ScOMBRESOCiD/E, gill openings wide; jaws more or 

 less prolonged ; maxillary and premaxillary free ; and the third upper pha- 

 ryngeal greatly enlarged. Scomberesox, bill-fish, Exoccetus, flying-fish. 

 Isteus, etc., cretaceous. BELONID^:, jaws greatly elongate, the lower the 

 longer ; maxillaries and premaxillaries closely united, third upper pha- 

 ryngeal not enlarged. Tylosurus, needle-fish ; Belone, bony gars, appears 

 in the miocene. 



ORDER IV. HEMIBRANCHII. 



Teleosts with the pharyngeals reduced in number, the lower 

 not united ; gills pectinate ; mouth bounded by premaxilla above ; 

 scapular arch connected to cranium ; ventrals sub-abdominal. 



