1 -lOH 



SCANDINAVIAN KISIIES. 



but liitlierto they have proved all hut fruitless. It has 

 been attempted, for instances, with dredges of a special 

 construction to collect in the clayey bottoms where the 

 (ilutinous Ha<j has its home deposited ova and fry in 

 course of devel(Ji>niont. l^irther experiments have been 

 made by keeping a nunil)er of Hags in aquaria, or Ity 

 sinking them in corves to the deptiis where they live 

 in a state of natui-e and examining at intervals the 

 contents of the corves; but all to no ])urpose. Yet it 

 is (juite possil)le that the (|uestion may be solved by 

 still more systematical and comprehensive investigations, 

 attention being paid to the biotic conditions of the Glu- 

 tinous Hag (the temperature of the water, the pressure, 

 etc.). Or perhaps, a circumstance of which the history 

 of science affords more than one example, a hajjpy ac- 

 cident may throw light upon the mystery. In any case 

 each new (lontribution to this result, each new sugges- 

 tion is of value. It is not yet known with certainty 

 whether the eggs are impregnated after or before their 

 deposition. W. Muller and Cunningham have described 

 a micropyle in the ripe eggs. x\n impregnation of the 

 ova after their exclusion from the parent-fish is ac- 



cordingly not impossil)le. N(jr is it known iiow and 

 where the eggs are laid, whether this is done on the 

 clayey bottom, as is most probable, or perhaps among 

 alga? on a rocky ground. It has been stated that the 

 TFlutinous Hag constructs with its slime a kind of 

 nest in the clay for the reception of its ova; hut 

 nothing positive is known on this head. It is not 

 known whether the embryos live in the clay or free 

 in the sea-water. Their appearance is utterly un- 

 known. Perhaps they are larval forms of quite a pe- 

 culiar ty|je, as the Ammocmtes form of Pefromyzou. 

 The smallest recorded specimens of the Glutinous 

 Hag, taken alone now and then in pots baited with 

 dead tisii, measure no less than 9 cm., and they 

 already conform in structure to the developed animal. 

 It consequently remains for the investigator to secure 

 them at earlier stages and, above all, to find new-laid, 

 impregnated eggs, as well as to watch the earliest 

 development of the embryos. This (juestion acquires 

 greater and greater biological importance year by year, 

 and it is to be hoped that the solution thereof will 

 not baffle research too long. 



THE GLUTINOUS HAG OR MYXINE (sw. pir.\len or pilalen). 

 MYXINE GLUTINOSA, Linn. 



Plate LIII, fig. 5. 



SaprnUiuinnl teeth hurjer in the anterior outer than in the poMerior inner row, and nicmberincj iji the former 7 

 or 'S, in the latter S — 10, the two foremost hein<i Jiesides continent at the tiase. 



Sijn. Pihrril \. Ingeris Pilt, Kalm, Besa .^'. Ainer., toni. I, p. 

 100. Hviid-Aal, Str6m, Sondm. Bedi:, pt. I, p. 287. 

 Sleensuer, Olav., Slcag. Beskr., p. 156, tab. 3, figg. .8 et 4. 

 Myxina glutinosa, LiN., Mus. Ad. Frid., torn. I, p. 91 (inter 

 Vermes), tab. VIII, fig. 4; Syst. Nat., ed. X, torn. I, p. 

 6.50 {My.vine); Gunnerus (Sleep- Marken), Trondhj. Selsk. 

 Skr., vol. II (1763), p. 2,50, tab. Ill; Penn. (Glutinous Hay), 

 Brit. ZooL, vol. IV (ed. 1777), p. 33, tab. XX, No. 15; 

 A. J. Ketz., Vet. Akad. Haudl. 1790, p. 110, tab. IV (sim. 

 cnni Petromyzonibus inter Vermes et Pisces interni.); Fabr., 

 Fna Groenl., p. 344 (inter Vermes); A. J. Rbtz., Fna Suec. 

 Lin., p. 301 (inter Pisces); A. RKTZ.,~~Vet. Akad. Handl. 

 1822, p. 233, tab. Ill; 1824, p. 408, tab. VI; Nilss., Pi-odr. 

 Ichttiyol. Scand..\). 123; J. MDr.i,., Vergl. Anat. Myxin., Abh. 

 Akad. Wiss. Berl., Pliys. CI., 1834. 1837, 1838; Sund., 

 V. Wr., Skand. Fisk., ed. 1, p. 121, tab. 28; Kr., Danm. 

 Fisk., vol. Ill, p. 1068; NiLss., Skand. Fna, Fisk., ip. 750; 

 Stui', Overs. D. Vid. Sels. Forh. 1864, p. 233; Couch {Borer), 

 Fisli. Brit. Isl., vol. IV, p. 408, tab. CCXLVIII, fig. 3; 

 Gthr, Vat. Brit. Mus., Fish., vol. VIII, p. 510; Putn., Proc. 

 Host. Soc. Nat. Hist. 1873, p. 135; Coll., Forh. Vid. Sels. 

 Chrnia 1874, Tilljegsh., p. 220; Malm, Gbgs, Bolt. Fna, 



p. 637 ; WiNTH., Naturli. Tidskr. Kbhvn, ser. 3, vol. XII, p. 



62; Mela, Vert. Fenn., p. 372, tab. X; Storm, Vid. Sels. 



Skrift. Trondhj. 1883, p. 48; Day, Fish. Gt. Brit., Irel, 



vol. II, p. 364, tab. CLXXIX, fig. 3; Cunningh., 1. supr. c; 



Nansen, 1. supr. c; G. Retz., Biol. Fiir. Forh. Sthlm, Bd 



I, p. 22, tab. Ill; Bd 11, p. 80, tali. Ill; Lii.i.j., Sc, Nor'j. 



Fisk., vol. Ill, p. 730. 

 Gastrobranclius cascus, Bl., Aual. F/.^rh., pt. IX, ]i. 67, tab. 



CCCCXIII. 

 .My.rine //«<«,(, GiR.. Proc. Acad. Nat. Sc. Philad. 1858, p. 223. 



The Hag that lives on the west ('oast of Swe- 

 den and in Norwegian waters has an average length 

 of 25 — 30 cm. Sometimes, however, individuals mea- 

 suring 45 cm. or a little more are met with. 



The hod// is of almost uniform thickness, for the 

 most part terete. Eel-like; behind the middle it shows 

 some lateral compression, and this is increased towards 

 the tail, which is thin, flattened, and somewhat dia- 



