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



except for one species of Anted 'on at the equatorial island Rolas. The only Actinometra 

 common to both sides of the Atlantic occurs at St. Paul's Rocks, and a few Caribbean 

 species both of this genus and of Antedon are common along the South American coast 

 as far south as Cape Frio (lat. 23° 1' S.); while in mid-Atlantic Antedon was dredged 

 in moderate depths near Tristan da Cunha and Ascension respectively. 



Closely allied to the North Atlantic species are those occurring at Kerguelen and 

 Heard Island, together with a couple of forms inhabiting the Strait of Magellan. This 

 Southern Ocean has also yielded Promachocrinus. the unique Tliaumatocrinus, and at 2600 

 fathoms a minute Antedon which was also found at 2900 fathoms in the North Pacific. 



Various Comatulae have been obtained at Simon's Bay, Natal, Madagascar, Zanzibar, 

 Mauritius, St. Helena, Rodriguez, the Red Sea, the Seychelles and Ceylon, with a 

 solitary species at Kurrachee, and in the Bay of Bengal. It is curious, however, that 

 none were found by Mr G. C. Bourne on the coral reefs of the Chagos group. But the 

 region in which Comatulae are most abundant is the great Eastern Archipelago, which 

 may be roughly described as a triangular area reaching 100° from east to west and 65° 

 from north to south, with its angles at Ceylon, Japan, and the Kermadec Islands. 

 Within this large area, which includes the Challenger Stations 170 to 236, Comatulae occur 

 in the most bewildering profusion. But, so far as I know, not one has been found on the 

 coasts of New Zealand, although Eudiocrinus and a ten-armed Antedon were obtained by 

 the Challenger at Station 169, within a comparatively small distance of the East Cape of 

 the North Island. The Challenger's dredgings between the Admiralty Islands and Japan 

 were among the deepest of the whole cruise, ranging between 1100 and 4475 fathoms, 

 and no Comatulae were met with between the equator and lat. 35° N. Three species were 

 obtained on the green mud off the Japanese coast between 345 and 775 fathoms, and one 

 in 2900 fathoms at Station 244 in the North Pacific. This form, Antedon abyssicola, 

 is the deepest Comatida known. 



From Station 244 until the Straits of Magellan were entered, the dredgings of the 

 Challenger yielded no Comatida at all, a fact which is the more interesting because 

 almost the same statement holds good for the Ophiurids. 1 



Single species of Antedon are known from the Sandwich Islands and Chile, and of 

 Actinometra from Tahiti and Peru ; but except for these and for the two in the Strait 

 of Magellan, I know of no Comatida in the Pacific east of long. 150° E., not even on the 

 western shores of North America. Antedon rhomboidea and Antedon magellanica, if they 

 can be called Pacific species at all, are the only ones in that ocean south of lat. 40° S. 

 None occur in New Zealand nor in Tasmanian waters. These two Magellan species are 

 therefore somewhat isolated, as on entering the Atlantic the Challenger dredged no 

 Comatulae until reaching Station 320, in 600 fathoms, where three ten-armed species of 

 Antedon were obtained. The Falkland Islands, however, seem to have yielded nothing. 



1 Zool. Chall. Exp., 1882, part xiv. p. 309. 



