170 



SCANDINAVIAN FISHES. 



THE RIVER BULLHEAD (sw. stensimpan). 

 COTTUS GOBIO. 



Plate VIII, fig. 1. 



Among the bones of the head only the anboperculum and preopercKltiin furnished n-ith spines, a)id onlij the upper- 

 most preoperctdar spine distinctly prominent, forminij a hook pointin// apirards iu a posterior direction, and cur- 

 red inivards, the second spine scarcely projecting above the skin, and tin- third apparent only as a tubercle. The 

 spine at the lower corner of the sidioperenhtm is directed forarirds, bat scarcely projects above the shin". The 

 distance, n-liich increases with age, betiveen the anal fn and the tip of the snout, in adult specimens at least, is 

 ncrer less than 48 % of the length of the body,, and the length of the base of the tin is under 48 % of this dis- 

 fdiice. The innermost ray of the ventral fins measures more than half their length. Branchiostegal membranes 

 united to and separated by the isthmus. The length of the maxillary bones is greater iu the male than in the 

 frmale and varies betu-een about 24 and 35 % of the length of the base of the second dorsal fin: the length of 

 the lou-er ja/r, wliicli is subject to the same difi'erence according to sex, varies between S3 and 44 % of the length 



of the base of the same fin. 



R. hv. (5: T>. 7'— 9|16— 18; A. 11—13; P. 13 

 , ; C. .i' + 8 1. O+.r; L. lat. por. 33 — 36. 



14; 



.S///i. Cottiis alepidotiis glaber, capite diacantho. Art., Gen., p. 48, 

 Si/ii., p. 76; jSpec, p. 82. 



Cotttis capitatns, LiN Miis. Ad. Frid., vol. I, p. 70. 



CoUns Got)io,Li}^., 6'i/st. Nat., ed. X, torn. I, p. 265; Fn. ^iwc, 

 fvl. 2, p. 115; Retz., Fn.Suec. Lin., p. 329; Cuv., Vai,., Hist. 

 Nat. Poiss., vol. IV, p. 145; Ekstr., Vet.-.\kad. Handl. 1831, 

 p. 308; NiLSS., Pvodr. Ichth. 6'cand., p. 98; Ekstr. et 

 Wricht, Skand. Fi.9k.. ed. 1, p. 34, tab. 7, fig. 2; Kroy., 

 Danm. Fiskc, vol. 1, p. 141; Sl'ndev., Ofvers. Vet.-Akad. 

 Forh. 1851, p. 185; Id., Stockh. L. Hush. Sallsk. Handl., 

 1855, p. 179; Nilss., .Skmid. Fn., Fid:., p. 64; Gthr, 

 Vat. Brit. Mas., Fish., vol. II, p. 156; Sieb. , iSnsswasser/. 

 Mitteleur., p. 62; Mgen, Finl. Fisk.,-p. 4; Ltkn, Vid. Meddel. 

 Naturh. For. 1865, p. 218; Lijjdstr., Gotl. Fisk. (Gotl. L. 

 Hush. Sallsk. Arsher. 1866) p. 14 (sep.); Bl.^nchard, Poiss. 

 d. eanx douces de la France, p. 161; Malm, Gbc/s, Boh. 

 Fn., p. 387; Feddersen, Natiuh. Tidskr. Kbhvii , ser. 3, vol. 

 XII. p. 73; Day, Fish. G:t Brit., IreL, vol. I, p. 46; Liu.,i., 

 Sc, Norij. Fisk., vol. I, p. 125; MOE., Hist. Nat. Poi.>!S. 

 Fr., vol. II, p. 293; MuB., Hcke, Fisch. Osts., p. 48. 



Cottus affmis, Meckel, Ann. Wien. Mus. Naturg., vol. 2 (18:'.6), 

 p. 146. 



Obs. In his Sijsttina Nalurcv (1. e.) Linn.kus lias overlooked 

 the circumstance that four years before he liad called this species 

 Cottus capitatns, deriving the specific name from Gesner (Gohio j/ii- 

 viatilis capitatns) De Aqnat., p. 477. 



This .species and the following one ave the smallest 

 (»f the true (Mti in Scandinavia. The usual size of the 

 River Bullhead, when full-grown, is between 75 and 100 

 mm., tliough specimens have been met witli up to a 

 length of 12.") nun.'. Small as is its importance in an 



economical respect, its interest from a scientific point of 

 view is nevertheless great, partly for its breeding habits, 

 and partlj' for the differences between it and its rela- 

 tives, wherein it represents the transition from the 

 genus Cottus to ('allionymus, Gobius etc. 



The body is of tlie usual round Cottoid-forin, ta- 

 pering like ;\ cone posteriorly: the sides of the tail are 

 somewhat compressed. The head, the length of which 

 varies between 25 and 27 % of that of the body, is 

 depressed and Ijroader than the trunk, but, like that of 

 the following species, differs from the others in the 

 following respects: it is entirely without projecting 

 spines or knobs and has no trace of the elevations 

 which appear in the other Colli on the top of the head. 

 It is tlius rounded evenly at the top towards the sides 

 and the snout, ^\•hich is also rounded anteriorly, and 

 flatter underneath. Tlie eyes* are set. on the slojje, 

 somewhat nearer the snout than the occiput, and at a 

 distance from each otlier which in adult specimens may 

 indeed l^e externally equal to the vertical diameter of 

 the eye, but if we measui-e only the least interorbital 

 breadth of the frontal bone, is at most ^/^ the hori- 

 zontal diameter of the eye. They project considerably 

 and are turned somewhat upwards'', a circumstance 

 wliicli causes the profile of the head to appear com- 

 pressed behind the eyes. The gape is liroad and almost 

 horizontal and the jaws project equally, but the upper 



" The spine whicli is situated at the lower posterior corner of the inleropercuhim and directed backwards, is present, but is extremely 

 indistinct. 



'' Sonictinies 6 according to Valenciennes and Lilljuroro, or 5 according to JIcjbius and Heincke. 



' MuBlus and IIisincke say even 150 mm. 



'^ Hence tlu! name of Uranidea, with a reference to the resemblance to Franoscopus (Gronov., Mus., 2, No. 166; Dekay, 1. c). 



