REPORT ON THE CRINOIDEA. 335 



Colour in spirit, — darkish-brown, with a dark medio-dorsal line ; the pinnules some- 

 times tipped with green. 



Disk 30 mm. ; spread 21 em. 



Locality. — Station 186, September 9, 1874; Prince of Wales Channel; lat. 10° 30' 

 N., long. 142° 18' E. ; 8 fathoms; coral mud. Three specimens. 



Remarks. — This fine species, which I have dedicated to the energetic curator of the 

 National Collection of Echinoderms, is readily distinguished from the two others which 

 have a similar arrangement of the palmar series, by the fact that its first and second 

 post-palmar series are only two-jointed ; so that on the outside of the ray there is no 

 pinnule between that of the second distichal and that on the second joint of the free arm. 



The difference in the lengths of the anterior and posterior arms is very considerable ; 

 and in each of the three individuals all the arms of the D ray are unprovided with 

 ambulacra, which may also be the case on the adjacent arms of the C and E rays as well. 

 This is well shown in fig. 2 on PI. LXIV. The C ambulacrum only supplies the anterior 

 half of the corresponding ray, 1 so that all the C 2 arms are grooveless. The same is the 

 case with all the arms of D and of E 2 , and even with some of those on E 1} as the groove 

 which supplies them suddenly ceases before reaching the level of the palmar axillary. 



One rather striking character of this species is the strong carination of the third and 

 following joints in the pinnules of the tenth brachial and its successors ; and another 

 peculiarity is the very definite nature of the perisomic plating between the rays. The 

 two radial axillaries are separated by a well-marked polygonal piece which rests on the 

 truncated angles of the second radials, and corresponds exactly with the first interradial 

 piece of the Apiocrinidae. 



One of the three individuals of this species was presented by Sir Wyville Thomson to 

 the Natural History Museum at Stockholm, where I found it in August, 1886. The other 

 two have yielded seven examples of Myzostoma. I could, however, find none of these 

 parasites when I first searched for them, and again when I examined the species for 

 descriptive purposes. But they seem to have become detached at a later period after the 

 type had been drawn, and they are therefore not yet described. 



6. Actinometra duplex, n. sp. (PI. LXIV. fig. 3). 

 Specific formula— a .3.|/^)3.(3).^- . 



Description of an Individual. — Centro-dorsal a rounded and slightly convex disk, 

 bearing some fifteen marginal cirri which have fourteen to seventeen tolerably uniform 

 joints. Three radials visible, the second partly united laterally ; the rays are quite free 



1 See woodcut, fig. 6 on page 274. 



