2 Thomson, Cavernnlaria, Liitkenii, Kdll 



contracted condition, they have an 8-lobed appearance with an 

 aperture in the centre. The tentacles are delicate and have 7 

 or 8 pairs of pinnules, the latter being smaller towards the 

 base. 



a l, c 



Fig. I. Showing the arrangement of the septa and position of the axis. 



The anthocodial part of the autozooid has apparently no 

 spicules, and may be 3 mm. in length and 2 mm. in diameter. 

 Some of the autozooids contain mature ova. In the contracted 

 condition, the diameter of an autozooid is about 1 mm., that of 

 a siphonozooid 0.015 mm. 



The siphonozooids are remarkably transparent, and so 

 numerous that it is difficult to estimate their relative number 

 as compared with the autozooids, but at one part, there were 

 30-35 siphonozooids between 4 autozooids. 'the siphonozooids 

 are surrounded by a ring-like layer of spicules. At the base of 

 the rachis, in the transitional part between the latter and the 

 stalk, young autozooids are present, along with numerous 

 siphonozooids between them. 



A transverse section near the base of the stalk shows two 

 large and two small compartments (text-figure ia), higher up 

 beneath the base of the rachis, the four compartments become 

 more equal in size. At the base of the rachis, there is an oval 

 central space divided into four nearly equal compartments, 

 with a rather soft axis in the centre, and the cavities of the 

 autozooids grouped externally around the four spaces (text- 

 fig, ib). In the head at a still higher level, the relative size 

 of the four cavities alters, and one has the condition shown 

 in text-fig. ic. . 



The axis, which is situated in the centre of the upper part 

 of the stalk and the lower part of the rachis, is a thin rod-like 

 structure, at one part 1 mm. in diameter; it appears to com- 

 mence as a central stiffening at the internal ends of the four 

 septa. 



