Sir Wyville Thomson likewise records the presence of a ten-armed variety in the
Faeroe channel at a depth of 610 fathoms, but gives no details of its characters.
A variation of secondary importance occurs in the character of the paxillse, by the
length of the spinelets of the crown being sometimes reduced to extreme shortness, and
thereby imparting to the paxillae the appearance of small granulate cones. This
condition, however, is in a great measure the result of abrasion, and is dependent
consequently upon the special nature of the locality; thus a Starfish inhabiting the
comparative calms of deep water would be subject to much less friction than one
frequenting a littoral district or amongst pebbly shingle.
The interbrachial spaces are also liable to change, being sometimes quite naked,
whilst in other cases they are more or less filled with paxillary spinulation.
Distribution.
a. Northward up Smith Sound: Discovery Bay, lat. 81° 41' N., 25 fms., hard
bottom (Nares’s Exped.), the most northern locality on record; Cape Frazer, 80 fms. ;
Franklin-Pierce Bay, 15 fms., bottom temperature'290,5 Fahr.
b. North o f American Continent'. Assistance Bay (Penny's Exped.), Newfoundland
(Verrill), Grand Manan (Stimpson), Massachusetts (Verrill, Gould, &c.).
c. North o f European Continent'. Spitzbergen (LUtlcen); Barents Sea, lat. 76° 58'
N., long. 45° 40' E., 110 fms. (‘ Willem Barents ’ Exped.); Finmark, Scandinavian coasts,
Iceland, Faeroe Islands (LutJceri); British coasts; French coast as far as the dept, of
Finisterre (.Liitken).
d. North o f Asiatic Continent: Behring’s Straits 1 (under the name of A. affinis,
Brandt).
Description o f the Illustrations o f this Species on Plate III.
Fig. 1. Abactinal aspect of a young specimen.
2. Actinal aspect of the same specimen: natural size.
8. Portion near the middle of a ray, actinal aspect: magnified.
4. Portion near the middle of a ray, abactinal aspect: magnified.
S olaster endeca ( Gmel.) , Eorbes., Plate III, Figs. 5-8.
1776. Asterias aspera, 0 . F. Müller, Zool. Dan. Prodr. p. 234. no. 2833.
1788. Asterias endeca, Gmelin, Syst. Nat. lin n . ed. xiii. p. 3162.
1816. Asterias endeca, Lamarck, Anim. s. Yert. vol. ii. p. 560. no. 23.
1828. Asterias endica, Fleming, Hist. British Animals, p. 487.
1834. Asterias (Solasterias) endeca, Blainville, Manuel d’Actinologie, p. 241.
1835. Asterias endeca, Johnston, Mag. Nat. Hist. vol. ix. p. 300, fig. 44.
1835. Stellonia endeca, Agassiz, Mém. Soc. Sci. Nat. Neufohâtel, vol. i. p. 192.
1839. Solaster endeca, Forbes, Mem. Wem. Soc. vol. viii. p. 121.
1840. Solaster (Endeca) endeca, Gray, Ann. & Mag. Nat. Hist. vol. vi. p. 183.
1841. Solaster endeca, Forbes, Hist. British Starfishes, p. 109.
1842. Solaster endeca, Müller & Troschel, System der Asteriden, p. 26.
1853. Solaster endeca, Stimpson, Syn. Mar. Invert. Grand Manan, p. 14.
1857. Solaster endeca, Lütken, Vid. Meddel. N. Forening i Kjöbenhavn, 1857, p. 35.
1861. Solaster endeca, Sars, Oversigt af Norges Echinodormer, p. 75.'
1862. Solaster endeca, Dujardin & Hupé, Hist. Nat. Zooph. Echinoderm.es, p. 354.
1865. Solaster endeca, Norman, Ann. & Mag. Nat, Hist. ser. 3, vol. xv. p. 122.
1866. Solaster (Endeca) endeca, Gray, Synop. Spec. Starf. Brit. Mus. p. 5.
1866. Solaster endeca, Terrill, Proceed. Boston Soc. Nat. Hist. vol. x. pp. 345, 356. «
1871. Solaster endeca, Hodge, Nat. Hist. Trans. Northumb. & Durham, vol. iv. p. 135.
1875. Solaster endeca, Perrier, Stdlérides du Muséum, p. 95 ; Arch. d. Zool. exp. et gén. vol. iv. p. 359.
Rays 8-11 in number, in length equal to, or only a little longer than, the diameter
of the disk. The disk is high and considerably arched, the rays being consequently
very deep at their base, with sides almost vertical, which gives an appearance of lateral
compression ; they taper rapidly towards the tip, however, and become round or sub-
cylindrical in shape. In the median interradial line, at the junction of neighbouring
rays, there is often a slight depression or furrow, which imparts a very graceful appear-*
ance to the Starfish. The abactinal calcareous network is very compact, the interspaces
being small and constricted. In large-sized specimens, each of the meshes upon the
disk and upper portion of the rays usually contain two (and occasionally three) papulæ,
but seldom more than one is present in small examples, and towards the extremities
of the rays. A paxilla or small tuft of spinelets (5 to 10 in number) springs
from each intersection, and these form regular parallel lines running obliquely from the
margin to the median line of the ray, in consequence of the symmetrical character of
the calcareous network and the diagonal arrangement of the ossicles across the ray»
10-12 paxillæ being counted in such a row at the extreme base of the ray.
The periproct is central and prominent, and the madreporiform tubercle is situated
in an interradium midway between the centre and the arm-angle. There are two rows
of ventro-marginal paxillæ, those of the upper series, although larger than the general
dorsal paxillæ, being very much smaller than those of the companion ventral series.
The paxillæ of the lower series are large and compressed in form; the lateral
expansion of the pedicle exceeds the thickness by seyen or eight times, and the longer
axis is placed at right angles to the median line of the ray. 40-50 of these large
paxillæ extend between the tip of the ray and the arm-angle ; the series is situate quite
over on the ventral surface, and runs with a curve round the margin of the arm-angle,
forming a continuous series with those from the neighbouring ray. The paxillæ which
bound the interradial area are very much smaller than those which occur upon the rays
proper.
Each adambulacral plate bears two sets of spines ;—One a small series, placed very
high up in the furrow and running parallel with it, which consists of two or three small
spines, the aboral being largest ; the other series forms a fan-like comb of six or seven
spines, connected by a membranous web, and is borne upon an elevated keel at right
angles to the furrow, almost concealing the small marginal series, which is placed deep
within the groove. The spinelets of the transverse series gradually increase in size as
they approach the furrow.
The interbrachial space, which is elongate, narrow, and sagittiform in contour, is
G