285 



GENUS PENNATULA. L. 



Pennatula indica, Thomson and Henderson. 



Two small colonies of this species as described in the " ' Investigator ' Deep- 

 Sea Forms". The following are the measurements in millimetres : — 



Total length of colony .... 

 Length of rachis ..... 



Breadth of keel 



Thickness of stalk ..... 

 Number of pinnules .... 



Length of largest pinnule 

 Breadth of insertion of largest pinnule 

 Number of polyps on largest pinnule 



The general colour is more yellowish, but this is due to a less degree of 

 development of spicules. On the upper surface of the pinnules there are only 

 bands of spicules, whereas on the type specimens the whole surface was covered. 

 Many of the polyps are not contracted and the longitudinal arrangement of 

 spicules on the tentacles is well seen. 



As an addition to the diagnosis we would note the presence of a single 

 sinuating row of zooids on the dorsal aspect of the keel touching the insertion 

 of the pinnules. 



The smaller specimen is too young to allow of accurate measurements and 

 estimation of numbers. 



Locality : Station 343, 23° 46' 15" N. and 58° 31' 50" E., 609 fathoms. 



GENUS PTEROEIDES, Herklots. 



General Note on the Gemis Pteroeides. 



This genus affords a good illustration of considerable variety within a 

 narrow range. In regard to the constancy of the number of rays — a feature to 

 which Kolliker gave much prominence — we counted the rays on all the pinnules 

 of ten specimens of P. punctatum, n. sp., and found a certain number (10) 

 almost constant, only varying by one on either side. But a similar enumeration 

 for P. crassum, Kolliker, revealed great variability (see Table), namely, 11-28. 

 As in many other cases it is necessary to take an assemblage of characters into 

 account in determining the position of a specimen of Pteroeides. 



