TRANSACTIONS OF SECTION D. 759 



62° S., while the corresponding limits for the Stalked Crinoids are 68° N. and 46° S. 

 Some genera, such as Actinometra and Pentacrinus, occur in shallow water 

 everywhere, or almost everywhere within the tropics ; though Pentacrinus has not 

 yet been obtained in the Pacific east of long. 170° YV., nor between the meridians 

 of 5° W. and 120° E., its nearest approach to the Indian ocean being the Moluccas. 

 Metacrinus, on the other hand, has been found in the neighbourhood of Singapore, 

 but it is otherwise almost entirely limited to the tropical regions of the We3t 

 Pacific, ranging, however, as far north as Japan ; while Pentacrinus Wyville- 

 Thomsoni occurs in the Atlantic as far north as lat. 45°. Holopus, however, has 

 never been obtained out of the Caribbean Sea. 



Of the stalked crinoids Bhizocrinus has the greatest northern range (68° N.)„ 

 but it has not been met with more than once, or possibly twice, south of the 

 equator, and is limited to the Atlantic and Caribbean Sea. Bathycrinus, while 

 ranging through 100° of latitude in the Atlantic and Southern Sea, does not occur in 

 the Pacific at all. Antedon, on the other hand, is cosmopolitan, five species 

 inhabiting the Arctic Ocean, while the genus is also well represented in the 

 Southern Sea. 



As a general rule the individual species of Crinoids are much limited in their 

 range, though there are a few well-marked exceptional cases. Both species of 

 Bhizocrinus occur in the east as well as in the west Atlantic, Bhizocrinus Lofo- 

 tensis ranging from the Lofoten islands to 0° S. , or perhaps to 35° S. While 

 three species of Pentacrinidre occur in the South Pacific near the Kermadecs, and 

 also among the Philippines. The four Caribbean species of Pentacrinus are widely 

 distributed among the West India islands, and it is very probable that systematic 

 dredgings in Oceania, like those of the Blake in the Caribbean Sea, woidd largely 

 increase the specific range, both of Pentacrinus and of Metacrinus. 



Among the Comatulse, the well-known Antedon Eschrichti is universally 

 distributed in the Arctic Ocean and on both sides of the Atlantic as far south as 

 lat. 43° N., while Antedon dentata of the Barents Sea, the north-east Atlantic, 

 and the Scandinavian coasts is abundant on the banks off New England. Antedon 

 carinata is another widely distributed species, occurring both on the Atlantic and 

 on the Pacific coasts of South America, at Java, Mauritius, the Seychelles, and 

 elsewhere ; while Actinometra pulchella of the Caribbean Sea has also been 

 dredged in moderately deep water off the coast of Morocco. The greater number 

 of the Comatulae, however, like the four species of Bathycrinus and most of the 

 Pentacrinidae have as yet been obtained at one or two localities only, and those 

 not very widely separated. 



The genus Pentacrinus has been found at all depths between 40 and 1,350 

 fathoms, though it has not been dredged more than sixteen times at a greater 

 depth than 200 fathoms, and only three times below 700 fathoms. It is abundant 

 in the Caribbean Sea, and has also been found in the east Atlantic, west Pacific, 

 and among the Philippines. The allied genus Metacrinus, on the other hand, has 

 a much more limited range, both bathymetrical and geographical, while it is 

 unknown in the fossil state, for it has only been dredged twice below 200 fathoms, 

 and never below 700 ; while, though extraordinarily abundant in shallow water at 

 certain localities in the Malay Archipelago, it appears to be confined to the warmer 

 parts of the western basin of the Pacific. 



Bhizocrinus, on the other hand, is almost entirely limited to the north Atlantic 

 and the Caribbean Sea, and has been obtained at all depths from 80 to l,900fathoms ; 

 it is fairly abundant down to 1,000 fathoms, though it is extremely rare below 

 that depth. Here, however, it is replaced by Bathycrinus.-which. has been dredged 

 eight times between one and two thousand fathoms, and once at 2,400 fathoms. 

 This genus ranges from the Atlantic into the Southern Sea, but is not known 

 elsewhere, nor does it occur in the fossil state as Bhizocrinus does. 



Two genera of recent Crinoids, Hyocrinus and Thaumatocrinus, have large oral 

 plates covering the peristome, and are thus to be regarded as in a permanently 

 larval condition. Both were dredged in the Southern Sea at depths of 1,600 fathoms 

 and upwards, and both have certain affinities with the Palseocrinoids. Hyocrinus 

 has a tripartite base, which occurs in no other Neocrinoid, while the arms are very 



