284 
SCANDINAVIAN FISHES. 
a: Base of the anal fin at least 10 
times the least depth of the tail 
(at least in adnlt specimens). 
Rays of the dorsal fin at least 
32, of the anal fin at least 26 Cyclogaster liparis. 
b: Base of the anal fin less than 9 
times the least depth of the tail 
(even in adult specimens). Rays 
of the dorsal fin at most 32, of 
the anal fin at most 25. Cyclogaster Montagui . 
MONTAGU’S SEA-SNAIL. 
CYCLOGASTER MONTAGUI. 
Plate XV, figs. 2 — 6. 
Hays of the dorsal fin 26 — 32, of the anal fin 22 — 25. Least depth of the tail more than 11 % of the length 
of the base of the anal fin. Length of the caudal fin more than 70 % of that of the head. Distance between 
the anal fin and the vent less than 1 / 3 of the distance between the former and the tip of the snout, and the dis- 
tance between the vent and the tip of the snout more than 1 / 4 of the length of the body. In adult specimens only 
one pair of nostrils, the posterior pair being covered by the skin. 
R. be. 6; D. 26—32; A. 22—25; P. 27—30; V. 6; 
C. tf+10 + .r; Vert. 35 1. 36. 
Syn. Gobius, Mull., Rtke, Zool. Dan., fasc. IV, p. 16 et 38, tab. 
CXXXIV et CLIV. 
Cyclopterus Montagui, Donov., Brit. Fish., vol. Ill, tab. 68; 
Mont., Mem. Wern. Soc., vol. I, p. 91, tab. V, fig-. 1; Cuv. 
( Liparis , subg.), Regn. Anim., ed. 2, tom. II, p. 346 ; 
Yarr. (Liparis), Brit. Fish., ed. 2, vol. II, p. 374; Kroy., 
Danin. Fiske, vol. II, p. 519; Voy. Scand. cett. . (Gaim.), 
tab. 13, fig. 1; Naturh. Tidskr. Kbhvn, ser. Ill, vol. 1, p. 243; 
Nilss., Skand. Fn., Fisk., p. 239; Gthr, Cat. Brit. Mus., 
Fish., vol. Ill, p. 161; Malm, Fork. Skand. Naturf. Mote, 
Sthlm 1865, p. 411; Gbgs, Boh. Fn., p. 451, tab. VII, fig. 
1; Malmgr., Ofvers. Vet.-Akad. Fork. 1867, p. 262; Coll., 
Fork. Vid. Selsk. Ckrist. 1874, Tilkegsh., p. 63; ibid. 1879, 
No. 1, p. 37; N. Mag. Natuvv. Christ., Bd. 29 (1884), p. 
64; Winth., Naturh. Tidskr. Kbhvn, ser. 3, vol. XII, p. 20; 
Hansson, Ofvers. Vet.-Akad. Forh. 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; Mob., Hcke, 
Fische d. Osts., p. 56; Lillj., >Sv., Norg. Fisk., vol. I, p. 
703; Hansen, Zool. Dan., Fiske, p. 40, tab. VII, fig. 1; 
Ltkn, Dijmphna-Togt. zool. bot. Udb., p. 139, cett. 
Cyclopterus (Liparis) liparoides + Cycl. (Lip.) gobius, Nilss., 
Prodr. Ichth. Scand., p. 62; Lip. gobius, Schagkrstr., Vet.- 
Akad. Handl. 1838, p. 248. 
Liparis lineatus + Lip. maculatus + Lip. Ekstromii, Malm, 
Forh. Skand. Naturf. Mote, Sthlm 1865, p. 412; Lip. vid- 
garis + L. macidatus + L. Ekstromii, Id., Gbgs, Boh. Fn., 
p. 447, tab. 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; Lip. vulgaris + L. Ekstromii, 
Hansen, Zool. Dan. Fiske, p. 41, tab. VII, figg. 2 et 3. 
The well-known shape of the tadpole is the most 
suitable expression of the shape of the body in this 
species, as well as in the two following ones. To the 
posterior extremity of the abdominal cavity the an- 
terior part 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 tins, 
the dorsal fin 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 fin, being always distinct from the latter. 
In the gravid female the greatest depth of the body 
may be as much as 1 / i of the length, and in the male 
as little as 1 / 5 . The difference chiefly lies, as usual, 
in the degree of distension of the belly. The greatest 
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 slight; but the latter is 
sharpened above, towards the dorsal edge; and though 
in young specimens it passes fairly evenly at the end 
of the abdominal cavity into the 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. (125 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 Finmark through Mr. F. Bull 
of Hammerfest, and is 101 mm. long. The longest 
Swedish specimen is a female 76 mm. in length, which 
