COMMON SKATE. 
1121 
( Dasybatus ex Blainv.), Bohusl. Fisk., G-bgs Welt., Witt. 
Samh. N. Handl., part. Ill (1819), p. 21 cum 2 tabb.; 
Fab. (Baja), Fiscli. Isl., p. 33; Nilss., Prodr. Iclithyol. 
Scand., p. 120; Yarr., Brit. Fish., ed. I, vol. II, p. 421; 
Fr., Vet. Akad. Handl. 1838, p. 158; Mull., Hle, Plagiost., 
p. 146; Kr., Damn. Fisk., vol. Ill, p. 978; Nilss., 
Slcand. Fan, Fisk., p. 739; Malm, Olivers. Vet. Akad. 
Forh. 1857, p. 193; Gthr, Cat. Brit. Mas., Fish., vol. VIII, 
p. 463; Ltkn, Vid. Meddel. Naturh. For. Kb*hvn 1873, 
p. 36; Coll., Forlr. Vid. Selsk. Chrnia 1874, Tillsegsh., 
p. 216; 1879, No. 1, p. 106; N. Mag. Naturv. Chrnia, 
Bd 29, p. 119; Malm ( Lceviraja ex Salv. et Bonap.), 
Gbgs, Boh. Fna, p. 615; Winth. {Raja), Naturh. Tidskr. 
Kbhvn, ser. 3, vol. XII, p. 60; Mor., Hist. Nat. Poiss. 
Fr., tom. I, p. 409; Mob., Hcke, Fiscli. Osts., p. 156; 
Day, Fish. Gt. - Brit. Irel. , vol. II, p. 336, tab. CLXVI; 
Lillj., Sv., Norg. Fna, Fisk., vol. Ill, p. 584. 
Ruia gaimardi, Robert in Gaim., Voy. Isl., Groenl., Zool., 
Poiss., tabb. 2 et 3 ; Dum., Hist. Nat. Poiss. (n. su. a Buffi.), 
tom. I, p. 565. 
Batis vulgaris, Coitch, Fish. Brit. Isl., vol. I. p. 87, tab. 
XVIII. 
Most of the common Skate taken in Bohuslhn 
measure between 12 and 15 dm. in length, but at this 
size are hardly mature. On the south and west coasts 
of Norway Krgyer met with specimens 22 — 25 dm. 
long and rising 200 Norwegian pounds (100 kilo.) in 
weight. 
The form of the body is rhombic, with the anterior 
side-margins somewhat undulate and more or less in- 
curved, the posterior, on the other hand, very faintly 
rounded (convex), with a slight incurvature just behind 
the tip of each pectoral fin. The distance from the tip 
of the snout to the hindmost part of the posterior 
margin of the pectoral tins is about 74 — 84 % (as a 
rule about 77 %), and to the posterior margin of the 
ventral tins about 80 — 94 %, of the greatest breadth of 
the disk. The greatest thickness (the depth at the 
shoulder-girdle) is about 7 or 8 % of the greatest breadth. 
The form and length of the head vary consider- 
ably, in proportion to the greater or less prolongation 
of the snout as mentioned above. The longitudinal 
diameter of the eyes is about 1 j 5 - — 1 / 6 of the length of 
the snout. The maximum diameter of the spiracles is 
about 3 / 5 — 4 / 5 of that of the eyes. The internasal width 
measures about 57 (in young specimens, according to 
Krgyer, sometimes 55) — 68 % of the distance between 
each nostril and the tip of the snout, which distance 
is about 88 (in young specimens, according to Kroyer, 
sometimes 91) — 83 % of the length of the snout. The 
breadth of the mouth is about equal in young speci- 
mens to the internasal width, in older ones perceptibly 
greater, at least 112 — 114 % thereof. The jaw-teeth 
are comparatively small (tig. 322). On a neck-like, 
but low base is extended an almost nail-headed disk, 
the posterior part of which rises in a somewhat conical, 
retral tip, short in the females (fig. 323), longer in the 
males. Teeth of this form are distributed in fairly 
regular rows, denser in young individuals than in old, 
both along and across the jaws. The largest teeth, with 
the longest cusps, are set in the middle of the mouth, 
Fig. 322. Half of a jaw in a male {A) and a female (B) of the 
common Skate {Raja hatis). Natural size. After Lutken. 
the smallest, with hardly a sign of cusp, innermost at its 
corners. As a rule the longitudinal rows number some 
40 — 50, the transverse 6 — 10. The various ages ex- 
hibit less difference in the number of the rows than 
in the form of the teeth, for in very small Skate there 
is scarcely an indication of the projecting cusps which 
are so prominent in older specimens, especially in the 
Fig. 323. A tooth of Raja batis, magnified. 
males; and the whole tooth thus acquires in the young 
a plane, lozenge-shaped appearance. 
The spiny armature of the body consists in very 
young specimens merely of a restricted number of ordi- 
nary aculei, namely two before and one behind each 
eye and a row along the upper median line of the tail 
with one or two spines between the two dorsal fins. 
Of spinulm there is not a sign in these young speci- 
mens, either on the dorsal side or the ventral, the 
body being smooth on both sides. In middle-aged in- 
