APHPODITA ACULEATA. 249 



1873. Aphrodita aculeata, Willemoes-Suhm. Zeitsch. f. w. Zool., vol. xxiii, p. 347. 

 1875. yi „ Mcintosh. Invert., &c, St. Andrews, p. 115. 



1879. „ „ Tauber. Ann. Danic, p. 78. 



1884. „ „ Y. Carus. Fauna Medit., p. 198. 



„ „ „ Webster and Benedict. Ann. Chset. Mass., Kept. Com. Fish and Fisheries, 



p. 699. 

 1886. „ „ Harvey Gribson. Vermes, Liverpool, Proc. Lit. Philos. Soc, vol. xl, p. 148. 



1888. „ „ De Saint-Joseph. Ann. d. Sc. nat. (7), vol. v, p. 146 (Polychast. Dinard). 



1890. „ ,, Malaquin. Ann. Boulon, 14. 



Habitat. — A. aculeata is by no means uncommon in deep water off the eastern 

 shores, indeed all round the British Islands. It generally frequents a somewhat soft 

 bottom. A specimen comes from 580 fathoms, on oozy ground in the Faroe Channel, 

 'Knight Errant,' 1880 ('Challenger Report,' p. 34). After great storms the beach at 

 St. Andrews is sometimes, e. g. in April, 1857, strewn with multitudes, so that the retiring 

 tide leaves a line of them for more than a mile. As the species is seldom encountered 

 within the bay proper, many were probably brought by the currents from the off-shore 

 grounds, such as near the Bell Rock and south-east of the Island of May. Grube, who 

 found it in the Adriatic (Lussin?), says that, according to Claparede and Malmgren, A. 

 aculeata is distributed both in the Atlantic and the North Sea, while Yon Martens found 

 it at Madeira. It extends to the shores of America (Massachusetts, &c), and a closely 

 allied species to the north-west coast, though the minute characters of the form from 

 the latter region have not yet received that attention necessary for certainty. 



The head in A. aculeata (Plate XXIV, fig. 6) is smoothly rounded in front, with a 

 median elevation posteriorly, and thus differs from that of Ldetmatonice filicornis. The 

 comparatively small, smooth tentacle proceeds from the centre of the anterior curvature, 

 and has a short basal articulation ; then it gently dilates to the somewhat clavate tip of 

 the central piece, the terminal portion beyond having a dilated basal region, after which 

 it narrows and ends in a slightly enlarged tip. The terminal articulation varies, being 

 longer in some, shorter in others, and often presents a fusiform outline, with the tip 

 slightly enlarged. A little behind the tentacle is, on each side of the median line, a 

 blackish or brownish area (in the preparations) — the eye. The palpi are proportionally 

 shorter than in Ldetmatonice filicornis, and taper gently from their basal articulation to the 

 tip. One is sometimes longer than the other — from reproduction of a lost organ. They 

 are papillose, as in L. filicornis, only the papillge are somewhat shorter. The facial tubercle 

 has sparsely distributed small globular papillse (Plate XXXYI, fig. 23), thus differing 

 much from L. filicornis. 0. G. Costa's fig. 2, Tav. i, therefore, is not an accurate 

 representation of the part in this species. 



Body. — The body is somewhat ovoid or broadly spindle-shaped, with the broad end 

 in front. The dorsum is convex, covered with the dense greyish felt in the middle, and 

 flanked by the gorgeously iridescent green and golden hairs and lustrous brown spines. 

 The scales are entirely concealed by the felt, while in it many foreign structures are 

 often fixed. Segments (bristled) forty-three. 



The ventral surface is flattened, and the skin is somewhat warty and rough, giving 

 rise to the somewhat fanciful comparison by Pallas to that of the shark, and often tinged 



