South African Alcyoiiacea. 
173 
in length from apex to extreme base. The spicules may be distinguished 
into club-like and more cylindrical forms. A striking feature of the polyp- 
bearing part is the manner in which the massive spicules project almost 
vertically upward at the bases of the polyps. The spicules of the polyp- 
bearing part are large clubs, and more cylindrical rod-like and spindle-like 
forms. There are few spicules in the interior either of the polyp- bearing 
part or of the stalk. The clubs of the polyp- bearing part are varied in size: 
some are from 0*24 x 0-12 to 0*98 x 0*28 mm., the more cylindrical spicules 
from 0-30 x 0*07 to 0-80 x 0*10 mm. In the external coenenchyme of the 
stalk clubs also occur, but they are rarer, the common type being more 
cylindrical. The clubs may measure from 0*30 X 0'12 to 0'58 x 0'38 mm., 
the more cylindrical forms from 0"28 x OTO to 0*86 x 0*2 mm. ; a few 
Fig. 5. — Spicules of Siyinlaria (Sclcrophytiim) unilobata, sp. n. 
exceptionally large spicules are 1*40 mm. in length by 0*22 mm. in diameter. 
A striking feature of the spicular arrangement of the stalk is the occurrence 
of very large spicules lying as a rule slightly internal to the smaller forms. 
The spicules of this species attain a large size. The following dimensions in 
millimetres of ten large spicules taken at random from the external part of 
the base of another specimen may be noted: 1-36 x 0-32; 1'40 x 0*28; 
1-40 x 0-32; 1-50 X 0-52; 1-60 x 0 34; 1-76 x 0*40; 1-94 x 0-30; 2-20 x 
0-38; 0-222 X 0-034; 2-60 x 0'04. 
I must here express my agreement with Cohn and Kiikenthal in the view 
that the genus Scleropliytum is identical with the genus Sinularia, and the 
latter name has priority. The present example of the genus Sinularia also 
shows certain resemblances with the genus Sarcopliytum. There is 
apparently a fairly close relationship between the three genera, Sarcoj)]iytum, 
Lohoijhytum, and Smularia, 
