310 THE VOYAGE OF II. M.S. CHALLENGER. 



joints below it, and a number of clawed hooks, the cirri, are pushed out from it. These 

 serve as grapnels, fixing the Feather-star to rocks or even to seaweeds, branching corals, 

 sea-firs, and sometimes to telegraph cables. The attachment is only a temporary one, 

 however, for the Feather-star may loosen its hold and swim about for a while, with a 

 very regular alternating movement of its arms, eventually settling down somewhere else. 



" The Comatulae are probably more abundant at the present time than in any former 

 period of the earth's history, rather more than four hundred species being known to 

 science. By far the greater number of them belong to one or other of the two genera 

 Antedon and Actinometra. These have five radial plates, resting directly upon the 

 centro-dorsal, and meeting one another laterally so as to form the greater part of the cup. 

 The rays borne by these plates may remain simple, as in the rare genus Eudiocrinus ; but 

 more commonly they fork, sometimes only once or twice, sometimes six or seven times, 

 so that the number of arms may vary from 10 to 100 or more. The mouth may either 

 be in the centre of the upper surface of the disk, as in Antedon, or it may be more or less 

 excentric, as in Actinometra. 



" The two species dredged at Station 48 belong to the first-named genus, and are 

 closely allied to the familiar rosy Feather-star of the British seas. They are both well 

 known Arctic forms, having been obtained by H.M.S. ' Discovery,' in 80° N. lat. Of all 

 the genera of recent Crinoids, Antedon is the one which has the widest range, both bathy- 

 metrically and geographically. While some species live in 5 fathoms of water or less, 

 others have been dredged at 2600 and 2900 fathoms, — depths from which no Stalked 

 Crinoid has been obtained. These, however, are isolated cases, for Feather-stars are but 

 rarely met "with at depths exceeding 200 fathoms. All the European and Arctic 

 Comatulae, with two exceptions, 1 and in fact the greater number of those inhabiting the 

 temperate zones, belong to this genus, which ranges from 80° N. lat. to 52° S. lat. Fossil 

 representatives both of it and of Actinometra occur in the Inferior Oolite of Gloucester- 

 shire, and are the oldest known Comatulae. 



"The dredgings at Cape York yielded a great number of the Feather-stars with an 

 excentric mouth, belonging to the genus Actinometra. The range of this type, both 

 bathymetrically and geographically, is much more restricted than that of Antedon. It is 

 almost exclusively a tropical genus, its northern limit being about 30° N. lat., and its 

 southern about 40° S. lat. Isolated species are known on the South African and South 

 Australian coasts ; but it is in the Caribbean Sea, in the Western Pacific, and especially 

 among the Philippines and the Moluccas, that the greatest variety is found. The 

 largest Comatulaj yet known belong to this genus, and also those with repeatedly branch- 

 ing arms. Few species of Antedon have more than forty arms, while there are several 

 Actinometra with one hundred arms, or even more. 



1 Actinometra pulchellu, Pourtales, a Caribbean species which the " Porcupine " found near Gibraltar ; ami Eudio- 

 crinus atlanticus, Perrier, which was dreilged by the " Travaillcur," 



