60 MEMOIRS OF THE QVEENSLASD MrSECM. 



suout, almost wholly scaly, the imieigerous system strongly developed. Mouth 

 terminal and somewhat pi-otractile; maxillary wholly or partly concealed 

 beneath the preoi-bital, without supplemental bone : chin usually ])origeious, 

 sometimes with a barbel. Teeth in the jaws usually in villiform bands, with or 

 without an outer enlarged row. sometimes uniserial; canines present or absent; 

 roof of mouth and tongue toothless. Two approxinuite nostrils on each side. 

 Preopercle usually with a feeble serrature ; opercle with two flat points. Dorsal 

 iin divided into two portions by a deep notch, the soft portion the longer, the 

 spinous depressible in a more or less complete groove. Caudal usually rounded 

 or euneate. Anal with one or two spines, much shorter thar. the soft dorsal. ^- 

 A'entrals inserted below or behind the pectoral-base, close together, each with i 5 

 rays, and with or without an axillary scale. Gill-openings wide ; gill-membranes 

 separate, free from the isthmus; seven branchiostegals : ])seuilobranehi;e usually 

 present ; gills four, a slit behind the fourth. Air-bladder, when present, mostly 

 large with many lateral appendages; otoliths of large size. Stomach ea^cal; 

 intestinal canal with two convolutions; pyloric appendages usually in small 

 number and weak. Suboeular shelf, when present, consisting of a small and 

 usually slender process of the second suborbital. Vertebrte 24 to 30; anterior 

 lirecaudals without parairophy.ses and with sessile ribs, the posterior ribs on 

 ])arapophyses. 



A large and important family of pereiform percoids, inhabiting the sandy 

 shores of all warm seas, except those of the Pacific Islands, from which, though 

 abundant on both shores of that ocean, they are unaccountably absent. They 

 freely enter estuaries, through which they make their way upwards, eventually 

 ascending the rivers to far beyond the influence of the tide. These excursions 

 are not, however, undertaken for the purpose of depositing their spawn, as in the 

 case of the salmon and shad, but primarily as predatory raids on the schools of 

 small nuillets, herrings, and prawns, which swarm at certain seasons in the 

 extratiilal reaches. Some species are, however, wholly confined to fresh water, 

 and it is possible that the ancestral seisenids were purely fluviatile, in which case 

 the excursions above referred to may be the outeome of an instinctive desire to 

 get back for a time at least to their original enviionment. Dr. Giinther takes a 

 converse view of the ease to that which I have hi*re advanced; he writes — "The 

 fishes of the '^feagi'e' family are chiefly coast-flshes of the troi)ical and suh- 

 ti-opical Atlantic and Indian Oceans, pi-eferring the neighbourhood of the mouths 

 of large i-ivers, into which they freely enter, s«»tf of the species having become so 

 completehj naturalised in fresh water that they are never found now-a-daijs in 

 the sea.'"-' I think, however, that to those wlio have pi'actical experience of these 

 fishes, the theory put forwai'd by ine above will appeal nmi-e sti'ongiy. Some of 

 the .species, such as thr Kastci-ti Allantic "maigre" {Sci(riia liolulepidota) ," our 



'" Kxcept ill Seriphun Ayres (Proc. Cal. Acad. S("i., ii, 1861, ii. 80), in whicli the anal fin is 

 at li'HSt as long a.s the soft dorsal. 



"Study of Fisiieg, 1880, p. 427, 



•' Lfihriis //o/o((7«V/ofi/,? Lacf-p^flo, Hist. Nat. Poi."a., iii, T802, p. .117. This name has tl 

 year's pri-fereu<'0 over Chriliidipterus at/iiila of the saiiio author — ilwd., v, ISOS, p, GS5. 



