26 



SCANDINAVIAN FISHES. 



have departed from the later opinion of Gunther and 

 others who have followed him, according to which 

 these fishes should be divided into two families. Some 

 exception, too, may Ix' taken to this arrangement, on 

 the ground that the characters given therein draw a 

 wide distinction between forms that are obviously most 

 closely related in other respects, e. g. Boccus and Perca. 

 The character given by Gl'nther, as well as by Jordan 



and Gilbert", as a distinction between these families, 

 tliat the PercidcB have fewer pyloric appendages than 

 the Serraniddi, does not hold good in the case of Boccus, 

 as B. lab rax has only 5 pyloric appendages'. The scheme 

 given above shows, however, that in the Scandinavian 

 Fauna we may follow the division proposed, whether 

 we decide to employ only external characters, or in- 

 ternal ones Avhich are not so easy to fix. 



Genus PERCA. 



The shape of the hodij an oblong oval, laterally compressed to some extent. The scales of average size, with sharply 

 denticulated margin. A spine behind the gill-cover. The preoperculum.i shoulder girdle and preorbital bones serra- 

 ted. The cheeks scaly, but the upper part of the head naked. Small teeth.^ of equal size, set in cardiform bands., 

 on the intermaxillary bones, the lower jaw, the vomer and the palatine bones. The tongue without teeth. Only 3 

 pyloric appendages. Pseudobranchice complete., though sometimes overgrown. Branchial membranes separate, each 

 with 7 rays. In the anterior dorsal fin from 13 to 15 rays. In the anal fin 2 spinous rays; the base being 

 shorter than that of the posterior dorsal fin. In the caudal fin at least 15 branched rays. 



As our knowledge of Perca Schrenckii of Turkestan 

 is only partial, and as Jordan and Gilbert'' have re- 

 ferred Perca gracilis of Canada to the common Ame- 

 rican perch, we can scarcely claim to know more than 

 one species of the genus Perca, our common perch. This 



species, however, contains several varieties, which are 

 spread over the east of North America, the ^vhole of 

 Europe and the west of Siberia, thus forming one of 

 the remains of the ])rehistoric connection across the 

 Atlantic between the Old World and the New''. 



THE PERCH. 



PERCA FLUVIATILIS. 



Plate 3, fig. 1. 



2 2 



n. hi: 7; D. 15 <> .; A. — 



P. 1 + 11 + 3' 



r. 



C. .!• + 



\3- 



15 + a;'; L. lat. 50—7 0. 



ib'.'/H. Perca Jiuviatilis et major auctormn, Art., Gen. Pise. p. 39; 



6'i/iion., p. G6; Descr. Spec, p. 74. 

 Perca jiuviatilis, Lin., Syst. Nat., ed. X, p. 289; Bi.och, 



Fische DeutsM., tab. LIT; Retz., Fn. Stiec. Lin., p. 335; 



Cuv., Val., Hist. yat. Poiss., II, p. 20; Pall, Zoo/jr. R. 



As., Ill, p. 248; Nilss., Proclr. Iclith. ScancL, p. 81; 



Ekstr., Wright, 6kand. Fiskar, ed. 1, p. 1, tab. I, fig. 



1; BONAP , Icon. Fn. Ital., Ill, n:o 87, p. 79, tab. fig. 1; 



Kr0yer, Dawn. Fishe. I, p. 1; Nilss., Skand. Fn., Fisk., 

 p. 5; GtJNTH., Brit. Mas. Cat., Fish., I, p. 58; Sieb., 

 Siissivasserf. Mitteleur., p. 44; Coll., Norges Fiske, Chr. 

 Vid. Selsk. Forh. 1874, Tilhogsh., p. 15; ibid. 1879, ii:r 

 1, p. 5; Malm. Gbgs, Boh. Fn., p. 374; Winther, Zool. 

 Dan., Fiske, p. 2, tab. I, flg. 1; Feddersen, Naturh. Tidskr. 

 Kbhvn, 3 R., XII, p. 71; Day, Fish. G:t Brit., Irel., I, 

 p. 2; LiLLJEBORG, Sv; Novff. Fiskur, I, p. 46; Reutee et 

 SuNDMAN, Finl. Fisk., tab. IX. 

 Perca vulgaris, Gronovius et Sch^effer; P. helvetica, Gron.; 

 vide GCiNTHER, 1. c. et Siebold, 1. c. 



" .Sun. Fish. N. Amer., 1. c, pp. 48fi and 527. 



* Cf. Day, Fish. G:t Brit., Irel., pt. I, p. 9. 



' Syn. Fish. N. Amer., 1. c, p. 524. 



<* Smitt: Ur var tids forskning no. 29, pp. 58, etc. 



' Sometimes 14, in the Anicriean variety sometimes 13. 



■'■ > 14. 



" » 9. 



' » 2 + 10 + 2 <ir 2 + 9 + 3. The middle figures indicate the number of the branched rays. 



' * ,r+ IG + ,r. The middle figure indicates the number of the branched rays. 



