MONOGRAPH OF THE EXISTING CRINOIDS. 529 



While at Bergen I examined several additional pentacrinoids secured by the 

 same expedition but not recorded in the published results. Two of these, one of 

 which is mounted on a slide, were taken on August 6, 1876, in latitude 64° 36' N., 

 longitude 10° 22' E., at a depth of 299 fathoms. There is no trace of cirri, and, 

 so far as can be determined, infrabasals appear to be absent. 



Another was dredged at Station 74 in August, 1876, at a depth of 612 fathoms. 

 There are about a dozen cirri, a pair, side by side, in each radial area, and one or 

 two additional. 



Two, one of which is mounted on a slide, were found on July 22, 1878, at 

 latitude 74° 54' N., longitude 14° .5.3' E., in 658 fathoms. One of these is rather 

 .stout in all its parts. There are 5 cirri, the largest with 15 segments. The 

 columnals are about 40 in number. In the distal portion of the column radicular 

 cirri and extra attachments are present, as described by Sars in Hathrometra sarsii. 



The arms of a pentacrinoid of this species at a stage when three or four 

 pinnules are present show large side and covering plates, as described by Mortensen. 



The Danish steamer Dijmfhna secured a single pentacrinoid of this species in 

 the Kara Sea (fig. 1226, pi. 37) which measured 21 mm. in length, the crown being 

 7 mm. and the column 14 mm. long. 



The column consisted of 37 segments and terminated in a strongly digitiform 

 terminal stem plate, recalling the same structure in Hathrometra sarsii. The 

 proximal columnals are short and discoidal. In the figure four are shown of this 

 type, including the centrodorsal, which decrease rather rapidly in diameter. The 

 following 12 are markedly swollen, especially the first six of these, their sides being 

 strongly convex in lateral view. In the distal six tiie swelling is confined to a 

 median zone, which appears as a narrow transverse band in lateral view. The 

 succeeding six are approximately cylindrical, or slightly broadened at the ends. 

 On the following six the sides are markedly concave in lateral view. Most of the 

 segments are provided with fairly regular parallel rows of small protuberances, 

 the regular arrangement of which is interrupted at the median transverse zone and 

 at the ends of the segments, which have concave sides. The oldest (distalmost) 

 columnals are quite without a regular arrangement of the small protuberances, 

 and the narrow median zone, representing the primitive annulus, has disappeared. 



The basals are still evident. 



According to the figure given by Levinsen five cirri, which reach to the fir.st 

 brachials, are present. 



On the distal portion of the arms a number of pinnules are present, the lowest 

 being on the thirteenth or fourteenth brachials. 



Doctor Mortensen has described two pentacrinoids of HelioTnetra glacialis from 

 Spitzbergen, one of which is in the Zoological Institute of T^psala and the other in 

 the Stockholm Museum. 



In the specimen at Stockholm (pi. 56, fig. 1354) the first pinnules and the 

 cirri have appeared. The crown is 5 mm. in length, and the column, in which 35 

 segments remain, but from which probably about 10 of the distal are lacking, 

 is 20 mm. 



