886 DR. J. STUART THOM,SOX ON 



the main axis. The sclerites vary considerably in size, but they 

 probably range from 0-085 x 0-153 to 4-0 x 2-0 mm. 



The diameter of a branch in the intervals between the 

 verticils is about 3 mm. 



The sclerites covering the axis have the following forms : — (1) 

 triangular, (2) quadrangular, (3) forms with curv^ed sides, and 

 (4) irregular forms. 



The systematic position of this species is near Stachyodes 

 trilepis Pourtales and Calyptrophora josephince Lindstrom. 



Locality, etc.— P. ¥. 11966. Cape Yidal (Natal), N.N.E. i N. 

 Similes. Depth, 80-100 fathoms. By dredge. Nature of bottom, 

 rocks. Date, February 27, 1901. 



Thouarella hicksoni, sp. n. (PI. XLIV". figs. 3 a & 6 ; 

 PI. XLY. fig. 1.) 



The colony is more or less bottle-brush-like, but it gradually 

 ta,pers off towards the apex. The dimensions of the colonies vary, 

 the largest specimen was 66 mm. in length and 25-28 mm. in 

 diameter. The central stem gives rise to the polyp-bearing 

 branches in a spiral manner. 



These branches vary in length, they are longer near the base 

 of the main stem, and gradually decrease in size towards the apex. 

 The branches are as a rule simple, but in some cases there are 

 secondary and tertiary bi'anches. The- primary'- branches are not 

 arranged in a regular spiral as the distance between their points 

 of origin is not the same in all cases. The interval between the 

 oi'igin of two primary branches on the central stem is frequently 

 about 1 mm= 



The axis is horny, flexible, yellow and iridescent, and its surface 

 is covered with imbricating spicules. It is more or le^s oval in 

 transverse section. When the spicules are removed from the 

 surface of the axis, fine longitudinal lines or strife are seen. There 

 are generally three spicules in a transverse row on the axis of a 

 branch. The diameter of a branch is about 0*391 mm.; that of 

 the horny axis about 0-136 mm. 



Most of the polyps are situated on the primary, secondary and 

 tertiary branches, but sometimes they occur on the centi-al stem. 

 On the branches they originate singly, and are disposed in a spiral 

 manner. The polyps are pear-shaped, and their surfaces are 

 covered by imbricating scales. The size of the polyps varies con- 

 siderably, the following dimensions may be noted : — (1) 1-088 x 

 0-629 mm.; (2) 0-476x0-306 mm.; (3) 1-343 x 0-595 mm. ; (4) 

 0-595 X 0-374 mm. ; (5) 0-935 x 0-663 mm. ; (6) 0-612 x 0-391 mm. 

 The interval on the branches between the polyps also varies but 

 not to any extent. The distance is generally from -5 to -6 of a 

 millimetre. In some polyps, the tentacles were extended beyond 

 the verrucfe, and the pinnules were seen, though not sufficiently 

 well to determine their number. There are on an average about 

 twenty-six spicules on each verruca and these are disposed in six 

 transverse (excluding tlie opercular spicules) and foiu- or five 



