SCI^NOIOS. 



49 



r AMU 



,v 8€IiENIDiE. 



K.ticnidl hones of flic head siuoolh, or the preoperculum and opercidum sli/jjitly denticulated. Scales slightly denti- 

 culated and extending more or less orer the vertical fins. When there are two dorsal fins, the anterior, ivMch is 

 slightly spinous, is shorter than the jxtsterior, soft-rayed fin: irhen the dorsal fins are united into one continuous 

 fin, the same relation holds good between the spinous-rayed and soft-rayed parts of this fin. The muciferous ducts 

 belonging to the system of the lateral line very much developed in the bones of the head. Simple, conical teeth 

 on the fides, bat the palate and tongue without teeth. Ventral fins thoracic, irith one spinous and five soft rays. 



As GuNTHEii" h;is ■•ili'cadx- ohscrvcd, tlie system of 

 the lateral line in its extension on the head in these 

 tishes follows the same tyfiical ai-rangement as in the 

 I'cst of the Acanthopterygians; it is only its high de- 

 gree of develojjment ' that, to some extent, may form 

 a character of the family, tliongh in Acerina and Roccus 

 we tind these sensoi-y organs but very slightly less de- 

 velo])ed. Connected \\itli the continuation of the scales 

 over some or all of the vertical tins, a character very 

 common among the Scicenidie, by which they range 

 themselves along \vith the Squamipinnes, ^ve tind the 

 continuation of the lateral line over the caudal tin, some- 

 times right to the hind margin. Another organ which 

 is generally very highly developed in the Scicenido}, is 

 the air-bladder", which, by its longitudinal division or 

 its appendages in the form of longitudinal tubes or trans- 

 verse, simple or complex excrescences, is probably con- 

 nected with the power which these fishes possess of 

 producing sounds audible at some distance''. 



In form of body these fishes are not very unlike 

 the Percoid family. The Scia;nidce might be considered 

 as Sea-perches with, as a rule, weaker fin-rays and scales 

 and also without palatine teeth, did not the dental equip- 

 ment of two Xorth American genera {Haploidonotus 

 and Pogonias) call for special notice on account of the 

 strength of the pharyngeals, ^vhicll is further increased 

 by the coalescence of the inferior pharyngeals, else a 

 character proper to the true Pharyngognates. This form 



of tiic pharyngeal dentition — obtuse grinding teeth 

 (molars) arranged like the stones of a pavement — reap- 

 pears in the jaw-teetli of tlie fishes belonging to the 

 Sparidcc. Another likeness between certain Scirenida; 

 and the Sparidce is the circumstance that, though in 

 the former the preorbital bones themselves do not cover 

 the maxillary l)ones, it is true, still this is done by a 

 dermal Hap fr(jm tlie suborbital ring, when the mouth 

 is closed. The Swedish name for the family, Hafgos- 

 fiskar (Sea Pike-perches), which has been introduced bj- 

 X1L8SON, is a suitable expression for the likeness of 

 these fishes to the Perches, a likeness which does not 

 vanish in their way of life. They are shore-fishes, 

 though many of them, being excellent swimmers, are 

 widel}' spread throughout the temperate and tropic parts 

 of the ocean, and, like the genus lioccus, they some- 

 times make their way to fresh water at the mouths of 

 large rivers or higher up the stream. The genus Ha- 

 ploidonotus, which we have just mentioned, and several 

 species of other genera have their constant abode in 

 lakes. In the Mediterranean the Sci(cni(l(e have been 

 known and valued from time immemorial; in the Red 

 Sea, according to GCxthek, they are wanting. Accord- 

 ing to the same author the familv includes about 130 

 species, distributed among 12 genera; Jordan and Gil- 

 bert', however, assume no less than 25 genera. In the 

 Scandinavian fauna only one of these genera can be 

 adduced, and that onlv as an occasional visitor. 



" Brit. Mus. Cat. Fish., II, p. 287. 



'■ Cf. Cuv., V.\L., Hist. Nat. d. Poiss., pi. 140. 



' Cf. Cuv., \m.., 1. c, pi. 138 and 139, and GC.nther, Study of Fishes, pp. 142 etc., or Handb. </. Ichth.. pp. 95 etc. 



'' Cf. W. Sokensen: Om Lydoryaner hos Fiske. Kblivn 1884, pp. 162 etc. and the passages there referred to. 



' Syn. Fish. X. Amer., Bull. U. S. Nat. Mus., No. 16, p. 566. 



Scandinavian Fishes. 



