284 



SCANDINAVIAN FISHES. 



Base of the anal fin at least 10 

 times the least deptli of the tail 

 (at least in adult specimens). 

 Rays of the dorsal fin at least 

 ;-?2, of the anal fin at least 26 Ci/olocfaster Ujjarig. 



Base of the anal fin less than 9 

 times the least depth of the tail 

 (even in adult specimens). Kays 

 of the dorsal fin at most 32, of 

 the anal fin at most 25 



Cyologaster Montagui. 



MONTAGU'S SEA-SNAIL. 

 CYCLOGASTER MONTAGUI. 



Rays of the dorsal fin 26 — 32., of the anal fin 22 — 25. Least depth of the tail more than 11 % of the length 

 of tlie base of the aval fin. Length of the raadal fin more thav 70 % of that of the head. Distance hetiveen 

 the anal fin and the vent less than Vs «/ i^'c distance hetiveen the former and the tip of the snont, and the dis- 

 tance hetiveen the vent and the tip of the snout more than ^! ^ of the length of the hodg. Tn adult specimens only 



one pair of nostrils, the posterior pair being covered hy the skin. 



R. br. 6; D. 26—32; A. 22—25; P. 27—30; T'. (5; 

 C. .r+10+.f; Vert. 35 1. 36. 



Syn. Gobius, MOll., Rtke, Zool. Dan., fasc. IV, ]). 16 ot 38, tab. 

 CXXXIV et CLIV. 



Ut/clopt.erus Montagui, Donov., Bi-ii. Fish., vol. Ill, tab. 68; 

 Mont., Mem. Wern. Soc, vol. I, p. 91, tab. V, fig. 1; Cuv. 

 (Liparis, subg.), Regn. Anim., ed. 2, torn. II, p. 346 ; 

 Yakr. {Liparis), Brit. Fish., ed. 2. vol. II, p. 374; Kruy., 

 Damn. Fiske, vol. II, p. 519; Voij. Scaiid. cett. (Gaim.), 

 tab. 13, fig. 1; Naturli. Tidskr. Kbhvn, set. Ill, vol. I, p. 243; 

 NiLSs., SIcand. Fn., Fisk., p. 239; Gthr, Cat. Brit. Mus., 

 Fish., vol. Ill, p. 161; Malm, Forh. Skand. Natiirf. Mote, 

 Sthlm 1865, p. 411; Gbgs, Boh. Fn., p. 451, fab. VII, fig. 

 1; Malmgr., Ofvers. Vet.-Akad. Forh. 1867, p. 262; Coll., 

 Forh. Vid. Selsk. Christ. 1874, Tilliegsh., p. 63; ibid. 1879, 

 No. 1, p. 37; N. Mag. Natiirv. Christ., Bd. 29 (1884), p. 

 64; WiNTH., Natm-h. Tidskr. Kbhvn, ser. 3, vol. XII, p. 20; 

 Hansson, 6tvfrs. Vef.-Akad. Fiirh. 1880, No. 4, p. 21; Day, 

 Fish. Gt. Brit., Irel., vol. I, p. 186, tab. LVI, fig. 2; Jord., 

 GiLB., Bull. U. S. Nat. Mus., No. 16, p. 743; MAb., Hcke, 

 Fische d. O.sts., p. 56; Lill.i., 6'v., Norg. Fisk., vol. I, p. 

 703; Hansen, Zool. Dan., Fiske, p. 40, tab. VII, fig. 1; 

 Ltkn, Dijniphua-Togt. zool. bot. Udb., p. 139, cett. 



Cyclopteriis (Liparis) liparnides + VycL {Lip.) gobius, Nilss., 

 Prodr. Ichth. Scand., p. 62; Lip), gobius, Schagerstr., Vet.- 

 Akad. Handl. 1838, p. 248. 



Liparis lineatus + Up. macitlatus + Lip. Elcstromii, Malm, 

 Forh. Skand. Naturf. Mote, Sthlm 1865, p. 412; Lip. vid- 

 garis + L. maculatus + Z/. Ekstromii, Id., Gbgs, Boh. Fn., 

 p. 447, fab. VII, fig. 2; p. 461, tab. VII, fig. 3; p. 464, 

 tab. VII, fig. 4; Lip. Ekstromii, Ltkn, Vid. Meddel. Naturh. 

 For. Kbhvn 1865, p. 221; Ljip. vulgaris + L. Ekstromii, 

 Hansen, Zool. Dan. Fiske, p. 41, fab. VII, figg. 2 et 3. 



Tlie ^v ell-known shape of the tadpole is the most 

 suitable expression of the shape of tiie body in this 

 species, as well as in the two following ones. To the 

 posterior extremity of the abdominal cavity the an- 

 terior ])art of the body is terete or, in the front part 

 of the head, even depressed; behind this point the tail 



is laterally compressed. The most remarkable departure 

 in Montagu's Sea-Snail from the tadpole form lies, 

 however, in the lack of continuity in the vertical fins, 

 the dorsal tin being generally entirely separate from 

 the caudal, and the anal fin, though it may sometimes 

 advance for some distance along the lower margin of 

 the caudal tin, being always distinct from the latter. 

 In the gravid female the greatest depth of the body 

 may be as much as ','4 of tlie length, and in the male 

 as little as Vs- The difference chiefly lies, as usual, 

 in the degree of disten.sion of the belly. The gi-eatest 

 breadth (thickness) is always somewhat, sometimes con- 

 siderably, less than the greatest depth, and in the male 

 may sink to about 15 % of the length of the body. 

 The difference between the breadth of the head and 

 that of the belly is always sliglit; but the latter is 

 sharpened above, towards the dorsal edge; and though 

 in young specimens it passes fairl}? evenly at the end 

 of the abdominal cavity into tlie compressed caudal 

 part, in older specimens, especially in gravid females, 

 the division between the belly and the tail is sharply 

 marked. The superior and inferior profiles of the tail 

 converge evenly towards the base of the caudal fin, 

 where the least depth of the tail varies between about 

 5 and 7 % (from 4"8 to 6'9) of the length of the body. 

 In the female, according to Day, the latter may be as 

 much as .5 in. (12.5 mm.); but we have no further in- 

 formation of specimens of this size. The largest .spe- 

 cimen of this species which the Royal Museum pos- 

 sesses, was received from Finmai-k through Mr. F. Bull 

 of Hammerfest, and is 101 mm. long. The longest 

 Swedish specimen is a female 7ti mm. in length, which 



