175 



Melitodes pulchella, n. sp. 



This now s])peies is based upon several slightly broken specimens. Three are 

 of a slightly pinkish tint and one is a beautiful white. The white colony mea- 

 sures aI)ont .")() mm. in height and 40 mm. in breadth. There are two main stems 

 from a spreading base 'io mm. in diameter. From these the remaining branches 

 arise dichotomously. The internodes vary in length from 1 mm. to lo cm. 



The largest pink colony is 70 mm. high and 25 mm. in breadth. The branch- 

 ing is api)roximately in one jilane, but in some cases one branch overlaps 

 another. The axis is 3 mm. in diameter at the base, and is very irregular 

 in outline, lieing penetrated by numerous large solenia and presenting indefinite 

 ridges on the surfiice. At the tips of the smaller branches the diameter de- 

 creases to I -75 mm. and the outline is more regular. 



The branching varies in the different parts of the colony, being indefinite in 

 the older parts, but dichotomous among the secondary branches which enclose 

 an angle of about 30°. There is no trace of anastomosing. The length of the 

 internodes is by no means constant, the first being 1 mm., the second 6 mm., 

 while among the smaller Ijranches 16 mm. is a common length. 



The nodes of the main stem are inconspicuous, being of the same diameter 



as the internodes and hidden by the coenenchyma. In the younger parts they 



are swollen and prominent, the red colour showing through the ctenenchyma. 



The cccnenchyma is packed with numerous spiny spicules presenting a 



rough glistening surface. 



The polyps are arranged differently in the several parts of the colony. On 

 the young branches they are disposed on the lateral margins, alternate, opposite 

 or indefinite. Further down there are two rows on each side, while near the 

 base they appear on three sides leaving a bare tract on the dorsal surface. 

 They are retractile within verruca? which are much more distinct on the younger 

 branches. When the tentacles are simply infolded the verruca? appear like 

 well-developed cylinders, Oo mm. high and 0-5 mm. in diameter, over which the 

 dome-like anthocodia? project, the base being broader than the top of the 

 cylinder. When the anthocodia? are fully retracted the verruca; are mound-like 

 and more inconspicuous. 



On the verruca? there are eight ridges formed by segregations of spicules. 

 The anthocodia? present a structure recalling the "crown and points" arrange- 

 ment of the Slplionoiionihi type, there being three or four rows of bent spindles 

 at the base of the tentacles, while on the tentacles themselves the spicules are 

 arranged " en chevron " enclosing an acute angle. 



The spicules of the coenenchyma are closely packed together and consist of 

 several distinct types. The following are some of these, with their measure- 

 ments in millimetres ; — 



