xxin OPISTHOMI PEDICULATI 7 I / 



two genera : Mastacembelus and Rhynchobdella. The largest 

 species reach a length of three feet. Little is known of their 

 habits. Of the Indian Hhynchobdella aculeata, Day says it 

 conceals itself in the mud and becomes drow r ned in water if 

 unable to reach the surface, as it apparently requires to respire 

 air directly. 



FIG. 433. Mastacembelus maculatus. x i. 



Sub-Order 12. Pediculati. 



Air-bladder without open duct. Opercle large, hidden under 

 the skin ; supraoccipital in contact with the frontals, separating 

 the parietals. Pectoral arch suspended from the skull ; no 

 mesocoracoid. No ribs, no epipleurals. Ventral fins jugular. 

 Gill-opening reduced to a foramen situated in or near the axil, 

 more or less posterior to the base of the pectoral. Body naked 

 or covered with spines or bony tubercles. 



A small, natural group, connected with the Acanthopterygii 

 Jugulares through the Batrachidae, in which the elongate pterygials 

 of the pectoral fin foreshadow the kind of arm ("pseudobrachium ") 

 which is more or less characteristic of these highly aberrant Fishes. 

 As in the Batrachidae, the post-temporal is flat and ankylosed to 

 the cranium, and the suprascapula is much elongated. The ptery- 

 gials, two or three in number, are separated from the small scapula 

 and coracoid by a broad ligament, the arm-like pectorals being 

 more or less distinctly geniculated and inserted far back behind 

 the cranium. The head is large, the basis cranii simple. The 

 gills are reduced to 2, 2|-, or 3. The spinous dorsal, if present, 

 consists of a few rays, which may be modified into tentacles 

 inserted on the head. Vertebrae 17 to 31. 





