Simpson — A Itcvision of the Gorgondlidae. 289 



Juncella juncea. 



In the Mergui Collection there are niinicrous specimens of this species ; 

 and a study of these has enabled me to define this species with some precision. 

 A superficial examination of these reveals two distinct types which, for the 

 present, may be regarded as varieties with the following distinction : — 



Var. a — with slightly protruding verrucae and with the polyps all over 



the coenenchyma. 

 Var. &— with markedly protruding verrucae and with two bare longitudinal 



spaces. 



I would emphasize the fact that these are but superficial differences, 

 and that no taxonomic importance can be attached to them — consequently 

 I refrain from naming them. I shall first examine them macroscopically 

 with regard to theii' superficial differences. 



Var. a. — Fig. 9 [a, h, and c) gives a very good impression of the external 

 appearance of this variety. The polyps are distributed irregularly over 

 the ivliole coenenchyma, so that, at any one level, the arrangement is the 

 same from any aspect. In the younger part of the colony — that is towards 

 the tip — the verrucae are slightly club-shaped, and are adpressed to the 

 axis, and are sunk in very shallow pits. About seven or eight may be 

 seen on one transverse line (fig. 9c). 



Towards the middle of the colony the number increases to nine or ten, 

 the verrucae project less, appear smaller, and are sunk in deeper pits. They 

 are not so closely packed as in the younger part (fig. 9&). 



Near the base of the colony the appearance is quite different. The polyps 

 are separated by intervals two, three, or more times the diameter of the 

 verrucae. They are much smaller than in the upper parts, and the verrucae 

 are now almost surrounded or engulfed by the coenenchyma (fig. 9J). 



Var. h. — (See corresponding figures, Via, b, and c.) 



In this variety the polyps are restricted to two definite longitudinal 

 series, separated by two bare spaces, whose position is marked by a more or 

 less distinct groove. Throughout the whole colony the polyps are more 

 protruded than in the previous variety. The colony is more slender and 

 tapering, and the coenenchyma is thinner. 



Near the tip of the colony there are usually two or three polyps in each 

 series (fig. 12c). 



Towards the middle of the colony four or five is a common nimiber in a 

 corresponding position. (Fig. 12i gives a view of the pit-tike depression in 

 the area devoid of polyps.) 



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