REPORT ON THE CRINOIDEA. 



347 



at the twenty-fourth node; (3) 22-5 cm. long, closed at the twenty-fifth node. The 

 individuals of this species present various forms of monstrosity, some of which have 

 already been mentioned : — (I) The presence of six joints in one ray, of which the second 

 and the axillary are syzygies, thus approaching the other group of Metacrinvs species. 

 (2) The presence of eleven radials on one ray, which recalls the irregularities of the 

 Palaeocrinoids. (3) The eighth joint of one of the primary arms is not a distichal axillary 

 as usual, but it is swollen and bears a slightly larger pinnule than the preceding joint, 

 so that it resembles an axillary with unequal faces. Fourteen joints further on there is 

 an axillary which corresponds to that on the secondary arms of other rays. (4) The 

 presence of a second smaller aual tube at the side of the ordinary one (PI. XXXIX. 

 fig. 2), an individual of Myzostoma u'l/ville-thomsoni, von Grafi", having attached itself 

 between the two. (5) The two arm-trunks borne by one of the palmar axillaries each have 

 a syzygy in the third brachial, and then unite again into a single trunk. The fourth 

 joint of the right-hand arm has the shape of an axillary reversed, i.e., it has two proximal 

 faces, one of which meets the epizygal of the third brachial, and the other the fourth 

 brachial of the left-hand arm. It bears a pinnule on its left side, and as it is the fourth 

 joint of one arm-trunk, and the fifth of the other, the ordinary sequence of the pinnules 

 is uninterrupted, and continues normal throughout the rest of the arm which is borne by 

 this reversed axillary. 



2. Metacrmus'cingulatus, n. sp. (PI. XL., PL XLI. figs. 1-4). 



Dimensions. 



Length of stem to thirty-third node, 



Diameter of stem, 



Longest cirrus (fifty joints), . 



Diameter of calyx, . 



Diameter of disk. 



Length of arm (one hundred joints), 



Length of large distichal pinnule (twenty-five joints). 



Length of first pinnule after tertiary axillary (fifteen joints). 



35-00 cm. 



5-50 mm. 



51-00 „ 



8-00 „ 



18-00 „ 



135-00 „ 



28-00 „ 



10-00 „ 



Stem robust, with a sharply pentagonal outline. Six to fifteen (usually eight to 

 twelve) internodal joints, with moderately crenulated edges. Their faces are bluntly 

 stellate, with shallow re-entering angles ; while their sides bear strong horizontal ridges 

 which are slightly more prominent at tlie angles of the stem, and are often marked by 

 irregular indentations. The nodal joints are more distinctly stellate, and have no ridges 

 except at the angles and where the cirrus-facets are absent. These reach closer to th-.' 

 lower than to the upper edges of the nodal joints, but the incision of the supra-nodals 

 is fau:ly distinct. The cirri have about forty to fifty tolerably uniform joints, and arc 



