188 Mr. G. A. Boulenoer on (lie Suborders and 



Suborder XI. Opisthomi. 



Air-bladder without open duct. Opercle well developed, 

 hidden under the skin ; supraoccipital in contact with the 

 frontal s, separating the parietals. Pectoral arch suspended 

 from the vertebral column, far behind the skull ; no meso- 

 coracoid ; no clavicle distinct from the cleithrum. Vertical 

 fins with spines. Ventral fins absent. 



This division stands in the same relation to the Acantho- 

 pterygii as the Apodes to the Malacopterygii. The single 

 family, Mastacembelida>, inhabiting the fresh waters of 

 Southern Asia and Africa, is possibly derived from the 

 Blenniida?. 



Suborder XII. 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 iu 

 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 Batrachida^, 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 Batrachidse, the 

 post-temporal is flat and ankylosed to the cranium, and the 

 suprascapula is much elongate. The pterygials, 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. 



Five families : — 



I. Gill-openiug in or behind lower axil of pectoral; mouth large, 



terminal or directed upwards. 



Pectoral fin scarcely geniculated ; ventrals present . 1. Lophiidce. 



Pectoral fin scarcely geniculated ; ventrals absent. . 2. Ceratiidce. 



Pectoral fin strongly geniculated ; ventrals present . 3. Antennctriidce. 



II. Gill-opening behind lower axil of pectoral ; mouth inferior ; 



\ entrals absent -1, Giycmtactimda:, 



