4io 



TELEOSTEI 



only, and are supplemented by two extensible lung-like air-sacs, backward 

 prolongations of the branchial chamber. 

 Amphipnous, Miill. ; E. Indies. 



FIG. 405. 

 Symbmnchus bengalensis, M'Cl., and upper teetli. (After Day, Fishes of India.) 



Series 4. 



Sub-Order 4. GASTEROSTEIFORMES (Catosteomi, Hemibranchii, 

 Lophobranchii). 



This sub-order is an assemblage of fish for the most part highly 

 specialised, which were first brought together by A. S. Woodward. 

 The Flute-mouths (Fistulariidae) and Sticklebacks (Gasterosteidae), 

 which Cope had already united in the group Hemibranchii, and the 



d. 



an 



pop. top. 



FIG. 400. 



Skull and pectoral girdle ofGasterosteusspinachia. an, angular ; ar, articular ; n.so, anterior 

 suborbital ; br, braiichiostegal ; cl, cleithrum ; co, coracoid ; d, dentary ; d.c, dennal coracoid 

 plate ; <?./, dorsal (in spine ; d.pl, dorsal dermal plate ; fr, frontal ; l.pl, lateral dermal plate ; 

 mx, maxilla ; n, nasal; no, nostril; op, opercular; pa, parietal; pmr, premaxilla; pop, pre- 

 opercular ; prf, prefrontal ; p&t, post-temporal ; ptf, postfrontal ; pt<\ pterotic ; q, quadrate ; 

 r, radial of pectoral fin ; sc, scapula ; sc.f t scapular foramen ; so, suborbital ; soc, supraoccipital ; 

 sop, subopercular ; st, suprateraporal. 



Pipe-Fishes (Lophobranchii of Cuvier), have been shown 'to be 

 related (A. S. Woodward [5051, Swinnerton [4311, Starks [4191 

 Gill [164]). 



The snout becomes greatly produced by the elongation of the 

 region between the orbit and the mouth ; the nostrils remain near 



