EEPORT ON THE CRINOIDEA. 191 



1G. Antedon abyssicola, n. sp. (PI. XXXIII. figs. 1, 2). 

 Specific formula — A.—. 



Centro-dorsal subconical, bearing about fifteen cirri. These have eight to ten joints, 

 of which the second is longer than wide and the following joints much elongated, the 

 fourth being about the longest ; the remainder diminish to the penultimate, which is not 

 much longer than wide and has a very faint opposing spine. 



Three radials visible ; the first and second about equal in length, the angles of the 

 former extending inwards and upwards for some distance, so that the second radials are 

 not united laterally. They are somewhat incised by the hinder angles of the rhombic 

 axillaries, the distal edges of which are much curved. Ten arms ; the first brachials 

 quite separated and more or less incised by the proximal angles of the irregularly 

 quadrate second brachials. The following joints are square till the second syzygy or 

 even slightly longer than wide ; the later joints obliquely quadrate and much longer 

 than wide, gradually becoming almost dice-box-shaped. Syzygies in the third, eighth, 

 and twelfth or thirteenth brachials, and then at intervals of two to four, usually three, 

 joints. 1 



All the pinnules are much broken, but they seem to have been slender and delicate 

 on the arm-bases. 



Disk and ambulacra naked ; sacculi small and rare. 



Colour in spirit, — white. 



Disk about 3 mm.; spread perhaps 5 cm. 



Localities.— Station 160, March 13, 1874; lat. 42° 42' S., long. 134° 10' K; 2600 

 fathoms ; red clay ; bottom temperature, 33°'9 F. One specimen. 



Station 244, June 28, 1875 ; lat. 35° 22' N, long. 169° 53' E.; 2900 fathoms; red 

 clay ; bottom temperature, 3 5° "3 F. Two specimens. 



Remarks. — This little species is one of very considerable interest, apart altogether 

 from the peculiarities of its calyx, for it is the only Comatula yet found at a greater 

 depth than 2000 fathoms. Bathycrinus, and perhaps also Hyocrinus, extend down to 

 2400 fathoms; Promachocrinus and Thaumatocrinus occur at 1800 fathoms, but with 

 the exception of Antedon abyssicola no other Comatulse have been found below 1600 

 fathoms, at which depth (Station 147) Antedon abyssorum, Antedon bispinosa and 

 Antedon remota were obtained. Antedon abyssicola has been dredged, however, at two 

 stations, one (Station 160) shortly before the Challenger reached Melbourne, where the 

 depth was 2600 fathoms, and the other in the deepest part of the North Pacific at 

 2900 fathoms (Station 244). Antedon abyssicola thus resembles Antedon alternata 

 in occurring at widely separated localities in the abyssal region, and it has some points 



1 In fie. 1 the tenth and fourteenth, and in fig. 2 the sixth brachials are wrongly drawn as syzygial joints. 



