4 THOMSON, The Pcnnatulaceae of the Cape of Good Hope. 



the rachis, including the autozooids is about 49 mm. The 

 expanded autozooids vary in length from 8 to 12 mm., 

 being on an average 9/8 mm. long. The distance between 

 the autozooids, taken transversely, varies from 1*4 to 

 2*4 mm., the average distance being r8mm. The width 

 of the stripes on which the autozooids are situated varies 

 considerably, being wider at the centre than at the apex 

 and base of the rachis. The width of these stripes varies 

 from 25 to 43 mm., the average being 3'5 mm. The 

 longitudinal distance between the autozooids varies from 

 1 or 2 mm. at the base of the rachis to 2, 3, or 4 mm. at 

 the middle of the rachis. The calyces of the autozooids 

 are 1 mm in height. 



The diameter of the siphonozooids is about o 0276 mm. ; 

 the diameter of the lower part of an autozooid in cross 

 section is about 1012 mm. Expanded tentacles are 

 approximately 1748 mm. in length, 0460 mm. trans- 

 versely at the base, and 0*184 mm. at the apex. 



The dimensions of the spicules are as follows : — 



The long spicules vary from 0*56 x 0*04 mm. to 

 066 x O 08 mm. The shorter spicules vary from 022 x 003 

 to 030 x 004 mm. The broad spicules vary from 

 011x003 to 030 x 005 mm. 



My specimen undoubtedly agrees in essential char- 

 acters with Kiikenthal's description of Actinoptilum 

 violle, only differing in minor points. The colour of 

 Professor Kiikenthal's specimens is slightly different. 

 The calyces of the autozooids of my specimen are 3 or 

 4 mm. less in height. Professor Kukenthal describes on 

 the calyces two large and six smaller teeth ; while the 

 two large teeth are apparent, the six smaller teeth are by 

 no means obvious in my specimen even with the aid of a 

 Zeiss binocular. As regards the spicules, those of the 

 external part of the stalk have lines running parallel with 



