io THOMSON, The Pennatulaceae of the Cape of Good Hope. 



No. of Colony. 



I. 



II. 



III. 



Length in mm 



I02 



70 

 20 

 32 

 *4 



66 



*7 



22 



13 



77 

 61 



18 



16 



*5 



Rachis. Length in mm 



Breadth in mm 



Stalk. Length in mm 



Breadth in mm 



The following are the chief characters of the speci- 

 mens : — 



Radial arrangement with curved rachis, no trace of 

 external bilateral symmetry, autozooids arranged in 

 transverse and longitudinal rows and provided with 

 calyces. Siphonozooids lying between the autozooids. 

 No axis. Spicules of rachis " dreifliigelig." No ventral 

 groove on the rachis. The authocodiae have spicules. 



In his diagnosis of the genus Actiuoptilum, Kukenthal 

 states that the autozooids have no spicules, if this were 

 to be taken as conclusive, then these specimens and 

 others already mentioned must be excluded from the 

 genus Actinoptilum. Kukenthal is probably right when 

 in discussing the genus Cavernularia he says that the 

 presence or absence of spicules in the polyps cannot be 

 regarded as a generic character. One might, however, 

 proceed a step further, and ask if the presence or absence 

 of the spicules in the polyps should be regarded as a 

 specific character. 



In the outer part of the stalk, the spicules are very 

 similar in shape to those described and figured for Actin- 

 optilum molle ; they are between 0*184 and 0024 mm - in 

 length. Among them are a few of the flanged type. In 



