MONOGRAPH OF THE EXISTING CRINOIDS. 573 



to 120 fathoms and at Skraaven in 200 to 300 fathoms) some very small free 

 individuals among a large number of mediiun size, none of which had the gonads 

 developed on the pinnules. 



Of these small specimens the largest, which is complete, has the arms only 14 

 mm. long, provided with 13 or 14 pairs of pinnules, which occur throughout their 

 entire length from the second brachial outward. The centrodorsal has about 20 

 cirri. 



The smallest, of which the arms are broken in their distal portion, is almost 

 equal in size to the largest of the pentaerinoids already described from the Lofoten 

 Islands, and a little smaller than that from Manger. The remaining portions 

 of the arms are entirely similar to those of the latter, but on the centrodoreal there 

 are only 15 cirri, of which the largest is only composed of 11 segments. This 

 individual has evidently only just been detached from the column. 



A third specimen, only very slightly larger than the last, still lacks some 

 pinnules on the lower portion of the arms, though Pj, which normally develops 

 before detachment, is present. 



Doctor Danielssen records that on Jime 9, 1876, the Norwegian North Sea 

 Expedition dredged a pentacrinoid of this species in latitude 61° 00' N., longitude 

 4° 49' E., at a depth of 200 fathoms. 



Doctor Mortensen compared directly pentaerinoids of ?I athrometra sarsii and 

 H. prolixa. While he did not find any differences of undoubted specific value in 

 the calyx, he found that the columnals of H. sars-ii differ conspicuously from those 

 of H. prolixa in being more robust and more constricted centrally. 



In addition to most of the specimens described by Professor Sars and by Doc- 

 tors Danielssen and Mortensen, I have examined the following: 



Off southwestern Norway (lat. 58° 32' N., long. 4° 18' E.), 280 meters; 

 April 30, 1908. 



A number of well-developed examples. 



Off southeastern Iceland (lat. 64° 16' N., long. 11° 04' W.), 192 fathoms. 



There are about 16 columnals, most of which are greatly elongated; the termi- 

 nal stem plate is slightly lobate: the radials are large, rhombic, just in contact 

 laterally. 



South of Iceland (lat. 63° 21' N., long. 16° 22' W.), 500 to 560 meters: 

 May 26, 1905. 



Two specimens; the larger has the crown about 10 mm. long and all the pin- 

 nules developed, and is apparently ready to discard the column; the broad thin 

 lobate column following the centrodorsal is typically developed : in the smaller the 

 pinnules are developed from the twelfth brachial onward. 



Southwest of Iceland (lat. 61° 44' N., long. 27° 00' W.), 485 fathoms. 



Total length about 12.5 mm. 



The coliunn consists of 35 columnals and a terminal stem plate. The nine 

 topmost coliunnals are very short and discoidal, very slightly larger in diameter 

 than those succeeding. The following increase in length to the fifteenth or six- 



