STARRY RAY. 
1109 
somewhat concave in the middle, from the hind margin 
of which a line, subulate cusp rises obliquely upwards 
and backwards. 
Only the upper surface of the body is armed with 
spines, the under being quite smooth and soft. The 
spinulae are of the same form as the aculei scattered 
over the whole surface, having a conically expanded, 
stellate base and an extremely tine, pungent tip. The 
only difference between them is in the size, though no 
such definite line as in the Thornback can here be 
drawn between the spinulae and aculei, large and small 
of all sizes being indiscriminately interspersed with one 
another, and their distribution being more scattered and 
irregular, leaving more or less extensive patches of 
smooth skin between them. The ordinary aculei occupy 
in young specimens the same positions as in young 
Thornbacks, and stand in nearly the same relation to 
one another; but their distribution is characteristic in 
three respects: there is no aculeus between the two 
dorsal fins“, which are set so close together that the 
membrane of the first often overlaps the anterior mar- 
gin of the second; the aculei along the spinal column 
are only 12 — 16 in number; and the scapular cartilage 
is always furnished with two aculei, one behind the 
other, and sometimes with a third, between this pair 
and the median series, all with deeply grooved, stellate 
base. In old specimens there further appears on each 
side of the median series a lateral row, commencing 
high up on the dorsal surface not far behind the sca- 
pular cartilage, and extending back to the first dorsal 
fin. On the tail these lateral rows lie about half-way 
between the median series and the side-margin of the 
body, and here the aculei never attain the same size as 
those of the median series. The lateral margins of the 
tail are never spinigerous. The extraordinary aculei 
appear, as we have mentioned, only on the dorsal side. 
They gradually increase in size, but never attain the 
same dimensions as the ordinary aculei on the spinal 
column. They are scattered with some degree of sym- 
metry, and are never wanting in adult individuals. 
Characteristic as the radiate base of the aculei 
generally appears in this species, it should be remarked, 
however, that during earliest youth, in individuals 9 — 
12 cm. long, the base is quite smooth, and the anterior 
aculei rise to a height of 5 mm. in a subulate form. 
Even at the former length of body all the ordinary 
a In adult Starry Rays from the Arctic regions, however, 
specimens from the White Sea there is no aculeus between these fins 
aculei are already present, and their length as just- 
stated is very considerable in proportion to the size of 
the body, as compared with their dimensions in older 
specimens, this being a sufficient character by which 
small young individuals of the two species may im- 
mediately be distinguished. 
The coloration is above of a plain liver-brown, 
faintly marbled with yellowish white, and thinly strewn 
with irregular, very indistinct, blackish spots of small 
size; but the large, round, whitish spots that appear 
in the Thornback are entirely absent. The spinulae 
and aculei are of a paler, yellowish white colour. The 
whole under surface is white, somewhat pinkish at the 
margins of the fins, the canals and pores of the lateral 
line being colourless. Kroyer remarks, however, that 
black spots, varying in number and size, frequently 
occur on the ventral side, especially on the under sur- 
face of the tail. Transverse bands may also be observed, 
but are less numerous than in the preceding species. 
A B 
Fig. 316. Jaw-teeth and aculei of a Starry Ray ( Raja radiata ), na- 
tural size. A: teeth of upper and lower jaws; a, tooth, magnified, 
lateral and superior aspects; B: dorsal aculeus, lateral and superior 
aspects, natural size; a , aculeus from the tail of a young specimen, 
lateral and superior aspects, magnified. 
The external difference of sex is less marked in 
young individuals of this species than in young Thorn- 
backs. In adult Starry Rays it is distinctly shown by 
the long pterygopodia of the male and by the posterior 
cards at the outer angle of the pectoral fins. The an- 
terior cards, on the other hand, at the side-margins of 
the head, may be regarded as wanting, for the female, 
which generally has more numerous spines, is, if any- 
thing, better armed at these spots than the male. 
The Starry Ray belongs to northern latitudes, and 
occurs far up in the Arctic Ocean. From Greenland 
it was described by Fabricius. The Norwegian North 
Atlantic Expedition of 1876 — 78 found it off Bear Is- 
land and the north-west corner of Spitsbergen. In the 
White Sea it was known even to Pallas. In the Bay 
of Biscay, according to Moreau, lies the southern limit 
Collett frequently found one aculeus between the dorsal fins. In our 
