REPORT ON THE CRINOIDEA. 355 



differentiated by Sir Wyville Thomson, and drawn on separate plates, do not seem to have 

 been kept apart by him ; and it is just possible that one individual of each may have been 

 accidentally interchanged. An additional reason for believing that this doubtful example 

 of Metacrinus varians really belongs to Station 214, and not to Station 170a, is that both 

 the Cirripedes [Scalpellum hcdanoides and Verruca nitida) which are attached to the 

 stem and cirri are recorded from Station 214, but not from Station 170a. 



The four individuals of Metacrinus varians which the collection contains present a 

 considerable amount of variation in several points of structure. One of them has a cirrus 

 missing at one of the nodes on the stem, while two more are undeveloped at another node. 

 The radials vary greatly, and present the following modifications, the second being a 

 syzygy in every case : — 



Three radiala, the axillary a syzygy. 

 Four radials, the axillary simple (type). 

 Four radials, the axillary a syzygy. 

 Five radials, the axillary a syzygy. 



In correspondence with this there is a great amount of variation in the size of the 

 basal joints of the lowest pinnules. For there may be sometimes only one, and some- 

 times two of these appendages in each interradial space ; and in the latter case the basal 

 joints of one or both of them are much smaller than usual. The size of the distichal 

 pinnules is also to some extent affected in the same way, the first one being frequently 

 much smaller at the base than its successors. 



Metacrinus varians is a species that stands very much by itself among those forms of 

 Metacrinus which have normally but four radials. It is smaller and less robust than all 

 the species previously described. From Meta^crinus angulatus and Metacrinus cingu- 

 latus it differs in the absence of the markings on the sides of the stem-joints 

 (PL XXXIX. figs. 3, 11 ; PI. XLI. fig. 1 ; PI. XLVII. fig. 6), and in the slightly shorter 

 internodes ; while in the types with smooth stems [Metacrinus nohilis, Metacrinus 

 murrayi, and Metacrinus superbus) the internodes are considerably longer than in the 

 more slender Metacrinus varians, and the grouping of the arm-divisions is different. 



6. Metacrinus moseleyi, n. sp. (Pis. XLV., XLVL), 



Dimensions. 



Length of tapering stem of young individual to twenty-third node. 

 Diameter of lower part of stem, .... 



Longest cirrus (forty-five joints), .... 



Diameter of calyx, ...... 



Length of the first radial pinnule (fifteen joints). 



Length of first pinnule after palmar axillary (thirteen joints), 



