206 



R. hi: C: D." 7\6~ 

 kit. por.' 25—29. 



A.'' 7 1. 8: 



SCANDINAVIAN FISHKS 

 P.' 16; V. V.,;6'/'.r+7+.r; 



7" 



Cottus cataphraetus, Fabh., Jul GroeiiL, p. 155 (nee Lix.). 



AffOHiis decagotms, Bi-., Si/st. IchtlnjoL, ed. Sciin., p. 105, fab. 

 27; Cuv., \'.\L., {Aspidophorns) Hist. Nat. Poiss., IV, p. 223; 

 Heinu., Dan. Vid. Selsk. Natiirli., Math. Afh.. V, Overs. 1829 

 — 1830, p. LIII; ibid. VII, pp. 114 ct 119; Kr., Naturh. 

 Tidskr. Kblivn, ser. 2, vol. I, p. 243 ; Id., I'oy. 6'cand., Lapp., 

 G.4IM., Poiss., tab. 5, fig. 1; Nilss., &'kand. Fu., Fisk., p. 88; 

 Gthr, (Agonus) Cat. Brit. Mtis., Fish., II, p. 215; Mgrn, 

 (A.?piilop/iorn.'<), Finl. Fi.4\fn., (disp.), p. 12; Id., Ufvers. Vet.- 

 Akad. FOrh. 1867, p. 260; Gill, (Archagonus) Cat. Fish. E. 

 Coast. N. Amer., Smiths. Misc. Coll., No. 283, p. 22 ; Coll., 

 {Agonns), Vid. Solsk. Foili., Chn.ia 1874, Tilhogsli., p. 40; 

 Ltkn, Vid. Meddel. Naturh. For. Kbhvn 1876, p. 381; Coll., 

 Norskc Nordh. Esped., Zool., Fiske, p. 44, tab. II, tig. 11 

 ct 12; Lillj., Si\. Norg. Fisk., I, p. 193; Jurd. {Agonus, 

 Podothecus) Proc. Acad. Nat. Sc, Philad., 1883, p. 293. 



Aspidophorus sptnosissimus, Kh., Naturh. Tidskr., 1. c, p. 250; 

 ]'og. iScand., 1. c, fig. 2; Gill (Leptagonus), Proc. Acad. 

 Nat. Sc. Philad. 1861, p. 167; — form. juv. demonstr. 

 Steenstr., Ltkn, Vid. Meddel. Naturh. Forh. Kblivn 1861, 

 p. 280. 



Aspidophorus malarinoides, EiD., Desl., Mem. Soc. Linn. 

 Norm., torn. 9, p. 167. 



According to the above remarks on the mutual re- 

 itions of the forms within this family, Af/oi/iis (h-caf/niiits, 

 1 form of body, occupies a higher place in the .scale 

 f development than the following species; but in most 

 ther respects it remains at a lower stage. The former 

 haracter is most clearly expressed, as usual, by the 

 roportions of which the least depth of the tail is a 

 ictor; and, connected with the elongated form of the 

 odv, we find the comparative!)- large number of plates 

 1 the longitudinal rows. These rows are anteriorly 8 

 I number, but on the tail, a little behind the second 

 orsal and the anal tin, are reduced to 6, owing to the 

 onfluence of the two neighbouring rows on the l)ack 



])ase of the caudal tin. Tlie anterior ])art of the lateral 

 line of the bodv is furnished witli al)oiit o (in young 

 specimens) or 7 (in old) .smooth, scaly plates, wliich it 

 pierces in the ordinarA- wav: and during this part of 

 its course the lateral line sloj)es do^vn from the u])per 

 corner of the gill-opening almost to tiie middle of the 

 side, vertically below the beginning of the tirst dorsal 

 fin, the point at whicli the upper of the two lateral 

 rows of spinous plates begins, while the lower has al- 

 ready begun at tlic middle of the axil of the pectoral 

 tin. The lateral line now rounds the up])er lateral row 

 of plates and riuis along the middle of tlie side to the 

 base of tlie caudal tin. At tlie beginning of its course 

 between the two lateral rows of plates it still opens 

 into a ])ore at each of the hrst two (perhaps three) 

 plates; liiit then these ducts become elongated and run 

 in the form of small lateral tubes along the lower side 

 of the lateral line proper, opening only at every second 

 or every third plate. Hence it follows that ^vhen, foi- 

 example, we can count 42 spinous plates in the lower 

 lateral row, we can find oidv 2!l pores in the lateral 

 line. On the head the system of the lateral line is 

 furnished with large muciferous pores, both undei' the 

 lower margin of the suborbital l)ones and in the louver 

 posterior margin of the preoperculum, where four cor- 

 ner-spines (most distinct in young specimens) — the 

 uppermost (hindermost) pointing backwards and upwards, 

 the corner-spine itself backwards and downwards, the 

 next downwards, and the first one f(.)rwards and down- 

 wards — form the boundaries of the muciferous pores 

 between them, which are continued, as usual, in a row 

 on tiie lower side of the branches of the lower jaw. 



nd the under side of the tail. On tlie back there are | The anterior nostrils are fairly large, cylindrical, der- 



or 6 plates in front of the first dorsal fin, which j mal ducts, turned outwards and set about half-waj' 



tself extends along 8 or 9 plates; then o or 4 (some- j along the snout; the posterior, on the other hand, are 



lines 5 according to Collett) similar pairs of plates i extremely small and very slightly raised ducts, set just 



letween this fin and the second dor.sal, which generally ' in front of the lower part of the anterior osseous boun- 



xtends along 7 plates. Behind this point 2 |)airs of i dary of the orbit (the ectethmoid bones). Just in 



dates may generally be distinguished, and then the front of the posterior nostrils lies a small i-ound hole 



wo rows coalesce, at first retaining a longitudinally ] or slightly raised; opening pore of the large muciferous 



iivided, su])erior ridge on the plates, the number of I canal which belongs to the system of the lateral line 



vhich we have found to be 18 or 16 (from 14 to 17 on the head. This canal is a continuation, on each 



iccording to Lutken) in this sim])le dorsal ro^\• to the | side of the snout, of the fi'ontal and occi|>itnl mucifer- 



" Z>P 5 or 0, according to Lltken; 5 — 7, according to Collett. 



'' A. 5 — 8, according to LDtken. 



' P. 14 — 16, according to Collett. 



** All the rays simple; 3 — 5 supporting rays above, and 2 or 3 below the 7 middle rays. 



' L. lut. por. 23-25, according to Collett. 



