146 



breadth, is separated by a constriction, and this part also bears polyps almost 

 over the entire hemispherical head. 



Both the colonies are stiff and rigid, owing to the dense network of large 

 warty spindles, which are quite visible to the naked eye. These are arranged 

 for the most part longitudinally, and their transparency gives the whole a 

 translucent sheen. Traces of the canals passing to the polyps can be observed 

 on the flat sides. 



The stem is traversed by several (about twelve) narrow cijenenchymal longi- 

 tudinal canals, which are almost equally distributed from the centre to the 

 circumference ; these are supported by very thick walls densely packed with 

 large tuberculate spindles. The canals pass upwards and branch, so that each 

 polyp is connected with the main portion by means of solenia. 



The polyps are situated on the edge of the flattened disc (like the flowers 

 in Celosia) in four to six indefinite rows. Each is supported by a hollow 

 cylindrical calycine portion To mm. in diameter, strengthened by large 

 longitudinally arranged spindles, the points of which project and form a pro- 

 tection for the completely retractile anthocodia. An aberrant polyp arises near 

 the middle of the flat disc ; a slight ridge marks the position of the canal 

 from which it takes its origin, and it is possible that this might have been the 

 origin of a lobe similar to that at the base of the colony. 



The anthocodia" (fig. 2) are about 1 mm. apart, and when exserted, but 

 with the tentacles infolded, have a height of about 275 mm. and a diameter of 

 1-5 mm. The "crown and points" arrangement described by Professor 

 Hickson for Chironephthya is a very prominent feature. The " crown " consists 

 of seven to ten rows of curved spicules placed circumferentially and loosely 

 interlocking. Surmounting this there are eight triangular points, each con- 

 sisting essentially of two large, slightly curved spindles enclosing an acute 

 angle and touching on their convex sides. Between these, however, there are 

 occasionally one or two smaller spindles disposed more horizontally. When 

 at rest the tentacles are simply infolded and overlap one another ; when ex- 

 panded they have a length of about 1 mm. ; their aboral surface is covered 

 with small scale-like spicules disposed " en chevron," but enclosing a very 

 obtuse angle. 



Ova, 0'3 mm. in diameter, are very abundant on the mesenterial filaments, 

 but, in spite of their large size, they showed, even when stained, no trace of 

 segmentation. 



The spicules are of three kinds, which correspond to the various positions 

 in the colony. The following are some of the measurements of length by 

 breadth in millimetres : — 



(A) Trunk and expanded disc portion — transparent spindles densely 

 covered with compound warts (fig. Sa) : — 



