322 THE VOYAGE OF H.M.S. CHALLENGER. 



where some of his other types are. I imagine, however, that it differs both from 

 Actinometra jimbriata and from Actinometra coppingeri, the middle arm-joints becoming 

 more oblong, and not remaining quadrate as in the latter type ; while the obliquity of 

 their surfaces in the lower joints seems to separate this form from Actinometra Jimbriata, 

 which it rather resembles in the number of its cirrus-joints. But there is a difficulty 

 in coming to a satisfactory conclusion about this point in the absence of Grube's type- 

 specimen. 



3. Actinometra multiradiata, Linn., sp. (PL LXVI. figs. 1-3). 

 Specific Jormula — a.3.2.[p.(p').6r.]. — . 



1758. Asterias multiradiata, Linnaeus, Systema Naturae, ed. 10, Holrnise, 1758, t. ii. p. 663. 

 1783. Asterias multiradiata, Retzius, K. Svensk. Vetensk. Akad. Handl., Ar 1783, t. iv. p. 241. 

 1788. Asterias multiradiata, Linnaeus, Systema Naturae, ed. 13, Lipsire, 1788, pars vi. p. 3166. 

 1805. Asterias multiradiata, Retzius, Dissertatio, sistens species cognitas Asteriarum, Lundee, 



1805, p. 35. 

 1816. Comatula multiradiata, Lamarck (pars), Histoire Naturelle des Animaux sans Vertebres, 



Paris, 1816, t. ii. p. 533. 

 1834. Comatula multiradiata, de Blainville (pars), Manuel dActinologie, Paris, 1834, p. 249. 

 1843. Asterias multiradiata, Miiller, Archiv f. Naturgesch., 1843, Jahrg. ix. Bd. i. p. 133. 

 1849. Comatula (Alecto) multiradiata, Miiller (pars), Abhandl. d. k. Akad. d. Wiss. Berlin, 



Jahrg. 1847 [1849], p. 261. 

 1862. Actinometra multiradiata, Dujardin and Hupe, Hist. Nat. des Zoophytes, Echinodermes, 



Paris, 1862, p. 210. 

 1879. Actinometra multiradiata, P. H. Carpenter, Trans. Linn. Soc. Lond. (Zool.), ser. 2, 1879, 



vol. ii. p. 27. 

 1882. Actinometra multiradiata, P. H. Carpenter (pars), Journ. Linn. Soc. Lond. (Zool.), 



1882, vol. xvi. p. 521. 

 1S82. Actinometra multiradiata, Bell, Proc. Zool. Soc. Lond., 1882, p. 533. 

 1882. Actinometra multiradiata, P. H. Carpenter (pars), Ibid., p. 747. 



Centro-dorsal a thick circular disk, often hollowed in the centre, and bearing fifteen 

 to twenty stout marginal cirri of twenty-two to twenty-six joints. The basal ones are 

 very broad, the sixth and seventh longer than wide, and from the tenth onwards the 

 joints bear dorsal spines. 



The ends of the basal rays are more or less visible. The first radials are almost 

 entirely concealed and sometimes parts of the second, which are imperfectly united 

 laterally. Three distichals, the third axillary with a syzygy ; two palmars, the second 

 axillary with a syzygy. Post-palmars, resembling the palmars, are but rarely present. 



Eighteen to twenty-four arms, of about one hundred and twenty to one hundred 

 and fifty short overlapping joints, which are triangular at the arm-bases, but become 

 discoidal towards the middle of the arm ; their distal margins are very spinose. 



A syzygy in the second brachial ; the next between the fifteenth and fortieth, with 

 others at intervals of four to nine joints. 



