MUSEUM OF COMPARATIVE ZOOLOGY. 173 



of the epizygal forms'a sharp angle which projects backwards into the retreat- 

 ing distal face of the hypozygal. 



E.\ami)les of this species were dredged by the " Blake " at the following 

 stations : — 



1878-79. No. 157. Off Montserrat. 120 fathoms. 

 No. 281. Off Barbados. 200 fathoms. 



Eemarlis. — This species is at once distinguished from P. dccorus by the short- 

 ness of the internodes of the stem and the absence of any enlargement at the 

 nodes. The calyx is closely similar to that of the variety of P. dccorus with 

 small basals, but the arm-bases have a totally different appearance from those 

 of tliat type, owing to the peculiar nature of the syzygy in the second brachials 

 and in the subsec[uent syzygial joints. The two apposed faces are not plane as 

 is usually the case, but the hypozygal has its distal face sharply incised, while 

 the proximal face of the epizygal is in two planes, which make a sharp angle 

 with one another and project backwards into the hypozygal. This peculiarity 

 is best seen in a side view of the arm, uidess the joints are separated by boiling 

 with potash or soda. The only other species of Fentacrinus in which it occurs 

 is the ten-armed P. narcsianus from the Western Pacific. In both cases it may 

 be traced in all the syzygies of the arms, so that small fragments of them are 

 easily recognizable. 



Botli the recent species of Rhizocrinus occur in the Caribbean Sea. 

 E. lofotensis was dredged in the Florida Straits by the late Mr. Pourtales, 

 a few months before the publication of M. Sars's well-known description 

 of it ; and /'. rawsoni, first found by the " Hassler " off Barl)ados, was 

 subsequently obtained by the " Blake " in 1877-78 and 1878-79. 



So far as my information goes, the distribution of these two species is 

 as follows : — 



R. lofotensis. 

 Bibb. 1868. Off the Samboes. 237 fathoms. 



Otf Sand Key. 248 and 306 fatlioms. 

 1869. Off C-ojima near Ihi,vana. 450 fathoms ; and several times at 

 lesser depths. 

 Blake. 1877-78. No. 29. Lat. 24° 36' N., Long. 84° 5' W. 955 fothoms. 

 No. 43. Lat. 24° 8' N., Long. 82° 51' W. 339 fathoms. 

 No. 44. Lat. 25° 33' N., Long. 84° 35' W. 53!) fathoms. 

 No. 56. Off Havana. Lat 22° 9' N., Long. 82° 21' 30" W. 

 175 fathoms. 



R. rawsoni. 

 Hassler. 1872. Off Sandy Bay, Barbados. 100 fathoms. 

 Blake. 1877-78. No. 32. Lat. 23° 32' N., Long. 88° 5' W. 95 fathoms. 

 Off Havana. 175 fathoms. 



