BY W. MACLEAY, F.L.S. 285 



Genus Leptocephalus, Gronov. 



Form compressed, elongate, band-shaped, body pellucid, 

 becoming white in spirits, like a tape worm ; skeleton entirely 

 cartilaginous. Fins generally rudimentary. 



Found floating in the sea. 



944. IjEptocepiialus Mobbisii, Gm. 



Gunth., Cat. Fishes, VIII., p. 139. — L. alius, Eichards. Voy. 

 Erebus and Terror, p. 51, pi. 30, figs. 8-10. (Perhaps another 



species.) 



Body compressed, its depth being about equal to the length 

 of the head. Sometimes the body sometimes the tail the longer. 

 End of the tail generally rounded. Snout obtusely rounded. 

 Eye rather large. Tongue distinct. Pectoral fins developed. 

 Jaws with or without small teeth. Chorda dorsalis without 

 ossifications. 



Australia. (Haslar Collection.) 



Family XVI. PEGASIME. 



Body entirely covered with bony plates, anchylosed on the 

 trunk and moveable on the tail. Barbels none. The margin of 

 the upper jaw is formed by the intermaxillaries and their 

 cutaneous prolongation, which extends downwards to the 

 extremity of the maxillaries. Gill-cover formed by a large 

 plate, homologous to the operculum, prseoperculutn and sub- 

 operculum ; interoperculum a long fine bone, hidden below the 

 gill-plate. One rudimentary branchiostegal. The gill-plate is 

 united with the isthmus by a narrow membrane ; gill-opening 

 narrow, in front of the base of the pectoral fin. Gills four, 

 lamellated. Pseudo-branchia; and air-bladder absent. One 

 short dorsal and anal fin, opposite to each other. Ventral fins 

 present. Ovarian sacs closed. 



