REPORT ON THE CRINOIDEA. 



3.53 



Togetlier with the two hirge specimens of Metacrimis nohiUs which agree very well 

 in their general characters, there was also obtained a fragment of stem which appears to 

 belong to this species. The iuternodes are much shorter than in the type, and contain a 

 number of thin joints which are evidently newly formed ; while there are traces of inter- 

 articular pores in its upper portion. As, however, the cirri are all directed downwards it 

 is possible that the individual was in a semi-free condition, with a comparatively short 

 stem like Pentacrinus maclearanus (PI. XVI.) or Pentacrinus alternicirrus. At one of 

 the nodes a cirrus-socket is totally undeveloped ; and the same appears to be the case at 

 another node farther down the stem, where a large Verruca covers the whole of one side 

 of the nodal joint, also extending on to those above and below it. 



Besides the two large specimens mentioned above there was also obtained at Station 

 192 a smaller individual which agrees so closely with the type of this species that I find 

 some difficulty in separating it, although the two forms appear at first sight to be totally 

 different. The stem, which is much more rounded than in the ty[3e (PI. XLI. figs. 7, 8), 

 is barely 5 mm. in diameter ; and although the internodal joints are generally smooth, 

 their angles are sometimes slightly produced outwards, while indications of horizontal 

 ridges appear here and there below the twelfth node. The grouping of the arm-divisions 

 is essentially the same as in the larger type, so far as can be made out in the fragmentary 

 condition of the dried specimen ; and in default of further information respecting 

 its characters, I do not see how to classify it otherwise than as an immature or smaller 

 variety of Metacrinus nobilis. 



5. Metacrinus varians, n. sp. (PI. XLIV. ; PI. XLVII. figs. 6-12). 



Dimensions. 



Length of stem to thirty-second node, 



Diameter of stem, .... 



Longest cirrus (fifty joints), . 



Diameter of calyx, .... 



Length of arm (ninety joints beyond palmar axillary 



Length of distichal pinnule (eighteen joints). 



Length of first pinnule after palmar axillary (nineteen joints). 



34-00 cm. 



5 •2.5 mm. 

 40-00 „ 



8-50 „ 

 85-00 „ 

 16-00 „ 

 1200 „ 



Stem moderately robust, with a simple pentagonal outline, its sides being nearly flat, 

 and scarcely grooved at all. Six to ten internodal joints (usually eight or nine), ■with 

 smooth sides and but faintly crenulated edges. Nodal joints bluntly stellate, with 

 moderately wide sockets which take wp their whole height, extending well downwards on 

 to the infra-nodals and also upwards on to the supra-nodals. Cirri of forty-five to fifty 

 very uniform joints, the lowest of Avhich are but little wider than their successors ; the 



(ZOOL. CHALL. EXP. — PART XXXII. — 1884.) li 45 



