310 Eev. T. Hincks on the 



figure, is that the groups of cells are more compact in V. Vido- 

 vicij and do not extend so far down the internode as in B. 

 pustulosa. In this respect it agrees with B. citrina, mihi, a 

 kindred form ; but as no mention is made of the remarkable 

 colouring which distinguishes this species, we have no suffi- 

 cient ground for identifying them. 



Family Buskiidse, Hincks. 



BuSKiA, Alder. 



BusTcia socialis, n. sp. (PI. IX. figs. 7.) 



Stem erect, slender, irregularly branched, branches long 

 and straggling. Zooeci'a developed in groups along the 

 stem and branches, usually separated by intervals, but occa- 

 sionally almost confluent, placed on different aspects of the 

 stem so as to surround it, comparatively large, elongate, 

 adherent for about a third of their length, rounded off" at the 

 lower extremity, the upper surface straight for some distance 

 above it, the anterior portion suberect and free, and closed 

 in below by a membranous area, which extends from the 

 point of adherence to the oral extremity ; one or two adherent 

 spinous processes given off" on each side of the cell just below 

 the area; cell elongate-flask-shaped, when the tentacular 

 sheath and setae are exserted (see fig. 7). 



B. sociaUs is a much larger species than B. nitens, Alder, 

 but about the same size as B. setigera, which I have lately 

 described from the Mergui Archipelago. It is distinguished 

 from its congeners by its erect and branching habit, as well 

 as by the form and grouping of its zooecia. The latter are 

 elongate and are placed length wiseupon the stem, one following 

 the other, but not on the same aspect of it. The decumbent 

 and adherent portion seems to be longer than in either of the 

 other species ; the anterior part slopes gradually upward, 

 expanding towards the oral extremity (PI. IX. fig, 7 a). 

 The whole of the front of the cell from the point of adherence 

 is closed in by a membranous wall. On the lower part of the 

 stem in the specimen examined the cells form a continuous 

 line ; but generally they are associated in groups of four or 

 five, which are separated by a distinct interval. The adherent 

 spines round the base of the cell, which are so characteristic 

 of B. nitens, are represented here by one or two short spinous 

 processes. 



The three species of Buskia which are now known consti- 

 tute a very good representation of the generic type. 



