no. 3647 PERCIFORM FISHES — GOSLINE 61 



In Mastacembelus liberiensis (USNM 118751), there are no pelvic 

 fins. The dorsal and anal rays are somewhat more numerous than 

 the vertebrae. The structure of the trunklike snout seems to be 

 unique in fishes. The nasal bone (Regan, 1912a, fig.) forms a long lid 

 over the nasal cavity. It is attached tightly by ligament to the 

 ethmoid medially and along its outer surface to the lacrimal. In the 

 cavity below the nasal bone, there is a long nasal organ of the same 

 gross shape as that of Anguilla; however, the nasal organ of 

 Mastacembelus is folded over on itself with the fold hinge medial. 

 The nasal epithelium extends down from the top fold and up from the 

 bottom one as a series of transverse leaves, and the water apparently 

 passes between the two folds. The posterior nostril is just ahead of the 

 eye, but the anterior is at the end of a tube at the front of the trunk. 

 Just above the anterior nostril on each side is the opening to another 

 long, membranous tube that connects posteriorly with the supra- 

 orbital sensory canal at the front of the nasal bone. The upper jaw is 

 suspended far forward, below the rostral "trunk," from a membranous 

 extension of the mesethmoid. The maxillary has no connection what- 

 soever with the palatines, and neither the premaxillary nor the 

 maxillary have the usual articular surfaces or pedicels. 



A fish that possibly is related more closely to the Congrogadoidae 

 than Mastacembelus is Alabes. In Alabes, the premaxillary pedicels 

 extend up under the nasal bones, as in Congrogadus, and the anterior 

 and posterior portions of the suspensorium are disconnected. Alabes, 

 however, is so specialized (degenerate) as to have obscured any real 

 evidence of relationship; Alabes has no supratemporal canal, no 

 dorsal or anal fin rays, and no primary pectoral girdle. Under the 

 circumstances, it seems best to leave Alabes, at least provisionally, 

 in the Symbranchiformes, where it usually is placed (Regan, 1912c). 



Superfamily Blennioidae (= Tripterygiidae, Clinidae, Chae- 

 nopsidae and Blenniidae). — Head compressed or rounded. Two 

 nostrils on each side. Gill openings more or less restricted below, the 

 gill membranes attached to one another or to the isthmus. Circum- 

 orbital bones usually firmly connected, without a subocular shelf 

 from the second. Medial tabular usually fused to the parietal. Front 

 and rear of suspensorium firmly connected. Prootic usually excluded 

 from the internal orbital border. Basisphenoid present. 



Pectoral actinosts columnar, longer than the scapula and coracoid 

 are broad (fig. lie), the upper pectoral ray articulating with an actinost 

 (except Tripterygiidae) . Pelvic fins with two to four soft rays of which 

 the outer are strengthened and the membrane between the rays 

 deeply incised (except such secondarily pelagic forms as Aspidontus, 

 Runula, Xiphasia). Dorsal and anal soft rays usually unbranched. 



