1104 
SCANDINAVIAN FISHES. 
Sectio I: Rajse clavatse, Rays. Snout short, its tip Hunt, the length of the snout from its tip to the 
centre of the eyes being less than 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 both with spinuhe 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 (sw. knaggrockan). 
RAJA CL A VAT A. 
Plate XL VII, figs. 1 and 2. 
Length of the snout ( from the anterior margin of the eyes) about 12 — 13 % of that of the body or 17 — 19 % 
of the breadth of the disk. Distance between each nostril and the tip of the snout at most about 15 % of the 
said breadth. Dorsal fins well separated, and the median line between them usually spinigerous. Aculei ungrooved, 
their number in the median line of the back and tail in front of the first dorsal fin about 26 — 30 % a . 
Syn. Raia clavata, Rondel., De Pise., lib. XII, cap. XIII, p. 353; 
Schonev., Ichthyol. Slesv. Hols., p. 58; Willughb., Hist. Pise., 
p. 74. Raja aculeata, dentibus tuberculosis, cartilagine trans- 
versa in ventre, Art., Ichthyol., 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, tom. I, p. 232; Bl., 
Fische Deutschl., pt. Ill, p. 65, tab. LXXXIII (9 + Raja 
rubus, p. 67, tab. LXXXIV, <p ); Ketz., Fna Suec. Lin., 
p. 304; Hollb. (p. p.), Gbgs Wett., Witt. Sainh. N. Handl., 
Ill (1819), p. 29 (nec fig.); Fab., Tidskr. Naturv. Kbhvn, vol. 
V (1828), p. 246; Yarr., Brit. Fish., ed. I, vol. II, p. 436; 
Fr., Vet. Akad. Ilandl. 1838, p. 140; Bonap. ( Dasybatis ), 
Iconogr. Fna Ital., Pesci, tab. 149, figg. 3 et 4 (+ D. aspera , 
ibid.); Ekstr., v. Wr. (Raja), SJcand. Fisk., ed. I, p. 154, 
tab. 35; Mull., Hle, Syst. Beschr. Plagiost., p. 135; Kr., 
Damn. Fiske , vol. Ill, p. 962; Nilss., Skand. Fna, Fisk., 
p. 735; Couch, Fish. Brit. Isl., vol. I, p. 99, tab. XXII; 
Gtiir, Cat. Brit. Mus., Fish., vol. VIII, p. 456; Coll., 
Forh. Vid. Selsk. Chrnia 1874, Tilliegsh., p. 214; N. Mag. 
Naturv., Bd 29 (1884), p. 118; Malm, Gbgs, Boh. Fna, 
p. 606; Winth., Naturh. Tidskr. Kbhvn, ser. 3, vol. XII, 
p. 60; Mor., Hist. Nat. Poiss. Fr., tom. 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., Man. Ittiol. Medit., fasc. 
Ill, p. 176; Lillj., Sv., Norg. Fisk., vol. Ill, p. 555; 
Carus, Prodr. Fnae Medit., vol. II, p. 521. 
Raja scabra, Lin., Mus. Ad. Frid., tomi II:di prodr., p. 52 
(sec. specimen ex Musseo Drottningholmensi). 
Raja Dasybatus punctatus, IIollb., Gbgs Wett., Witt. Samh. 
N. Handl., pt. IV (1821), p. 25 cum tab. 
Raja pontica, Pall., Zoogr. Ross. Asiat., tom. Ill, p. 58; Rathke, 
Mem. div. sav. etrang. Acad. Sc. Petersb., tom. 111(1837), p. 309. 
Raja Rubus, Nilss. (ex Bloch), 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, they 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 developed. 
The disk is rhombic, with somewhat pointed pec- 
toral and ventral fins. 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 fin (the length of the disk) is on an average" 
75 %, to the anterior angle of the cloaca 64 % d , and 
to the tip of the posterior ventral lobe 84 % e , of the 
breadth of the disk. 
a Provided that the series be complete, no aculei having been lost. 
b In 1 1 specimens 36 — 92 cm. long. The variations run between 65 '/ 2 % and 72 1 /., /• 
c The variations run between 71 % and 79 %. 
d ,, ,, ,, ,, 6lV 2 % and 68 %. 
e ,, ,, ,, ,, 79 % and 91 "/. 
