1104 



SCANDINAVIAN FISHES. 



Sectio I: Rajse clavatse, Rays. Snout short, its tip hh(nt, the length of the snout from its tip to the 

 centre of the ej-es being less thnn half its breadth at the latter point. 



These species are the smallest, or at least do not attain the same magnitude as the Skates. The females 

 are larger than the males and more plentifully armed bi)th with spinuhu and aculei. Spines of the latter kind, 

 known by Fries as extraordinary aculei, occur, sometimes in considerable number, scattered here and there on 

 the body without definite arrangement and often without symmetry. Iris furnished with lobate lid overlapping 

 the pupil (Fries). 



THE THORNBACK (.-w. knaggeockan). 

 RAJA GLAVATA. 



Plate XLVII. fitrs. 1 and 2. 



Length of the snout (from the anterior margin of the eges) about 12—13 % of that of the hodij or 17 — 19 % 



of the breadth of the disk. Distance beticeen each 'nostril and the tip of the snout at most alwut 15 % of the 



said breadth. Dorsal fins well separated, and the median line hctn-een them usualhj spinigerous. Aculei ungroored, 



their number in the median line of the back and tail in front of the first dorsal fin about 26—30 %'. 



Syn. Raia clavata. Rondel., De Pise, lib. Xll, cap. XIII, p. 353; 

 ScHONEV., Ichthjol. Slesv. Hols., p. 5S; Willvghb., Hist. Pise, 

 p. 74. Baja aculeata, dentibus tuberculosis, cartilagine trans- 

 versa in ventre, AuT., IclUliyol., Gen., p. 71; Synon., p. 

 99; Spec, p. 103; Lin., Fna Suec, ed. I, p. 100; It. 

 Westrog., p. 175. 



Raja clavata, Lin., Syst. Nat., ed. X, torn. I, p. 232; Bl., 

 Fische DeutscliL, pt. Ill, p. 65, tab. LXXXIII (? + Raja 

 rubus, p. 67, tab. LXXXIV, (^); Retz., Fna Suec. Lin., 

 p. 304; HoLLB. (p. p.), Gbgs Wett., Witt. Samh. N. Handl., 

 Ill (1819), p. 29 (nee fig.); Fab., Tidskr. Naturv. Kbhvn, vol. 

 V (1828), p. 246; Yarr., Brit. Fish., ed. I, vol. II, p. 436; 

 Fk., Vet. Akad. Handl. 1838, p. 140; Bonap. {Dasybatis), 

 Iconogr. Fna Ital, Pesci, tab. 149, figg. 3 et 4 ( + 2>. aspera, 

 ibid.); Ekstr., v. Wb. {Raja), Skand. Fisk., ed. I, p. 154, 

 tab. 35; Mull., Hle, Syst. Beschr. Plagiost., p. 135; Kr., 

 Damn. Fiske, vol. Ill, p. 962; NiLSS., Ska?id. Fna, Fisk., 

 p. 735; Couch, Fish. Brit. Isl., vol. I, p. 99, tab. XXII; 

 Gtjir, Cat. Brit. Mus., Fish., vol. VIII, p. 456; Coll., 

 Forh. Vid. Selsk. Chrnia 1874, Tillfegsh., p. 214; N. Mag. 

 Naturv., Bd 29 (1884), p. 118; Malm, Gbgs, Boh. Fna, 

 p. 606; WiNTH., Natnrh. Tidskr. Kblivn, ser. 3, vol. XII, 

 p. 60; Mob., Hist. Nat. Poiss. Fr., torn. I, p. 391; MOb., 

 HcKE, Fisch. Osts., p. 154; Storm, N. Vid. Selsk. Skr., 

 Trondhj. 1883, p. 45; Day, Fish. Gt. Brit., Irel., vol. II, 

 p. 343, tab. CLXXI; Doderl., Ulan. Ittiol. Medit, fasc. 

 Ill, p. 176; LiLLJ., Sv., Norg. Fisk., vol. Ill, p, 555; 

 Carus, Prodr. Fnoe Medit., vol. II, p. 521. 



Raja scabra, LitJ., Mus. Ad. Frid., tomi II:di prodr., p. 52 

 (sec. specimen ex Musaeo Drottningliolmensi). 



Raja Dasybatus punctatus, Hollb., Gbgs Wett., Witt. Samh. 

 N. Handl., pt. IV (1821), p. 25 cum tab. 



Raja pontica. Pall., Zoogr. Ross. Asiat., torn. Ill, p. 58; Rathke, 



Mem. div. s.iv. etrang. Acad. Sc.Petersb.,toni.III(1837),p.309. 



Raja Rtibus, NiLSS. (ex Block), Prodr. Ichthyol. Scand., p. 118. 



The males attain a length of about 7 dm. from the 

 tip of the snout to the end of the tail; the females 

 sometimes measure 9 or 10 dm. Until they have reach- 

 ed or nearly reached this size, the}- are apparently 

 incapable of propagating their species; Fries at all events 

 never found an individual under 6 dm. in length with 

 the external or internal genital organs develojjed. 



The disk is rhombic, with somewhat pointed pec- 

 toral and ventral tins. The anterior side-margins of the 

 body form two bends, the anterior situated just behind 

 the tip of the snout, where a small, blunt muzzle is 

 thus produced, the posterior beginning a little in front 

 of a transverse line drawn through the centres of the 

 eyes. The posterior side-margins are more convex, but 

 in their outer parts curve slightly inwards. The great- 

 est breadth of the disk is on an average' 69 % of the 

 length of the body. The distance from the tip of the 

 snout to the extreme end of the hind margin of the 

 pectoral tin (the length of the disk) is on an average" 

 75 ?», to the anterior angle of the cloaca 64 %'', and 

 to the tip of the posterior ventral lobe 84 %% of the 

 breadth of the disk. 



** Provided that the series be complete, no aculei having been lost. 



' In 11 specimens 36 — 92 cm. long. Tlie variations run between 65' 



' The variations run between 71 °i and 7 9 %. 



'' „ „ „ ,, ei'/o % and 68 %. 



< ,, 79 % and 91 'i. 



ad 72'/, %. 



