REPORT ON THE CRINOIDEA. 105 



sharpened and form a keel. The third brachial has a similar but smaller pinnule with 

 flattened outer side. The next two pairs of pinnules have broad and carinate lower 

 joints, and the later pinnules are more stylifomi, with the two basal joints expanded and 

 trapezoidal, and the following ones elongated. Disk thickly covered with plates which 

 extend out on to the arms at the sides of the ambulacra, and also over the genital glands. 

 Pinnule-ambulacra have well defined side plates and covering plates. Sacculi very rare. 



Colour in spirit, — light whitish-brown. 



Disk 11 mm.; spread probably 20 cm. 



Locality. — Station 214, February 10, 1875; off the Meangis Islands; lat. 4° 33' N., 

 long. 127° 6' E.; 500'fathoms; blue mud ; bottom temperature, 41 °'8 F. Two mutilated 

 individuals, and one younger. 



Remarks. — The very stout cirri of this fine species are as long as those of Antedon 

 longicirra, though consisting of fewer joints. This is owing to the greater length of the 

 first twenty joints in those of Antedon valida, as will be evident from a comparison of 

 the figures on Pis. XV. and XVII. The two species also resemble one another in the 

 almost entire absence of sacculi. Although I have examined many pinnules of Antedon 

 valida, there is only one in which I have been able to distinguish the sacculi at all 

 clearly ; and even in this there are not more than about a dozen on the whole pinnule. 

 They are sufficient, however, to show that sacculi may be present in Antedon longicirra, 

 Antedon acutiradia, and other species, although I have not been able to find them 

 on those pinnules which I have examined for the purpose. 



Antedon valida and Antedon longicirra are, however, very distinctly separated by 

 the characters of the pinnules borne on the second brachials. In the latter species this 

 pinnule is comparatively inconspicuous and smaller than its successor ; but in Antedon 

 valida, as in Antedon incerta, it consists of short and wide joints, the lowest of which are. 

 flattened on the outer side, where they meet those of adjacent rays, and cut away on the 

 inner, so as to give a very singular appearance to the basal part of the pinnule, which it 

 is not easy to describe. It is well shown, however, on PI. XV. figs. 5, 6, and PI. XVIII. 

 fig. 5, and it reappears in a modified form in Antedon lusitanica (PI. XXXIX. fig. 2). 

 This flattening on the outer side of the first pinnule is much better marked in Antedon 

 valida than in Antedon incerta. But in both species alike the second brachial itself is 

 not much flattened on its small outer face (PI. XV. fig. 6), though its inner side and that 

 of the hypozygal of the third brachial are distinctly flattened (PI. XV. fig. 5 ; PI. XVIII. 

 fig. 5), while the outer face of the hypozygal is in no way specially marked. The distal 

 pinnules of Antedon valida are remarkable for the expanded and trapezoidal shape of 

 their two basal joints (PI. XV figs. 7, 8), a feature which scarcely appears at all in 

 Antedon incerta, though it is characteristic of the group of European and Circumpolar 

 species of which Antedon eschrichti is the type (PI. XXIV. fig. 13). 



(ZOOL. CHALL. EXP. — PART LX. — 1887.) OOO 14 



