148 



DR A. MILNES MARSHALL ON THE 



Japan ; and from the middle of the North Pacific Ocean. Umbellula has, 

 therefore, of all genera of Pennatulida, the widest distribution. "* 



The " Triton " specimen makes a very interesting addition both to the list 

 of species of Umbellula and to the localities in which it has been found. 



The measurements of the sole specimen of Umbellula gracilis yet known are 

 as follows : — 



Total length, . 







290 mm 



Length of rachis (dilated part), 







26 



Length of polyp-bearing part of rachis, 







18 



Width of rachis at widest part, 







6 



Thickness, . 







5 



Length of terminal dilatation of stalk, 







35 



Diameter, .... 







3-2 



Diameter of stalk (middle of length), 







07 



„ stem, 







0-5 



„ stem (widest part), 







0-9 



Number of polyps, . 







13 



Length of polyp (shortest), . 







15 



body, 







7-5 



„ tentacle, . 







7-5 



Length of polyp (largest), 







26 



body, 







13 



„ tentacle, . 







13 



Diameter of polyp, base, 







5 



„ just below tentacles, 







2-8 



Length of zooid, largest, 





• 



1-8 



Length of tentacle of zooid, largest, . 







1-3 



General Observations. 



Geographical Disti 'ibution . 



Horizontal Distribution. — The most noteworthy point is the great abundance 

 and variety of specimens dredged at one particular locality, — Station 11. At 

 this place there were obtained, from a depth of 555 fathoms, nineteen specimens 

 of Pennatula phosphorea var. aculeata; three specimens of Virgularia tuber- 

 culata, a new species ; one specimen of Diibenia dbyssicola var. smaragdina, a 

 form hitherto found only off the Norwegian and Swedish coasts ; thirty speci- 

 mens of Kophobelemnon stelliferum var. dura ; and one specimen of Umbellula 

 gracilis, a new species ; i.e., example of five out of the fourteen known families 

 of Pennatulida, of three distinct subsections, and two of the four sections of 

 the order were obtained at this one spot. 



; * Kolliker, Zool. Cliall. Exp., part ii. 1880, p. 37. 



