1906.] ALCYONARIANS FROM ZANZIBAR. 401 



The beginning of a differentation of calyx and anthocodia in 

 C. margaritiferce may be regai'ded as a hint of the Symjjodmin 

 type ; the slight union of the bases of the polyps in C. mollis may 

 perhaps be regarded as pointing towards the Xenia type. 



Clavularia GARCiiE Hickson. 



Several specimens appear to be referable to this species, if its 

 diagnosis is made rather more elastic. 



The polyps are 10-13 mm. in length, with thin transparent 

 walls, and show no sign of being able to contract. Mr. Crossland 

 states that the living forms had very mobile tentacles opening and 

 closing regularly. 



The tentacles are from 6-8 mm. in length and have the pinnules 

 arranged so as to leave a wide bare space on the oral and a 

 narrower bare space on the aboral sui-face. The long pinnules 

 are in one row and they vary in number from 16 to 30 on each 

 side. There is occasional simulation of two rows. 



The fact that the pinnules vary from 16-30 pairs shows that 

 the number of pinnules is not in itself a character of much 

 diagnostic importance. 



Minute, slightly i-oughened, rod-shaped spicules are abundant 

 throughout the colony and give it a peculiar glistening appearance ; 

 they are from 0'04-0"05 mm. in length and 0*007 mm. in breadth. 

 Hickson describes the spicules of G. garcicB as scattered and not 

 crowded ; they are here densely crowded. 



Locality. Ohuaka, E. Zanzibar. Previously from Ohagos 

 Archipelago. 



In another group of polyps, which we are inclined to refer to 

 the same species, there are some interesting differences. The 

 bodies of the polyps are more substantial, but they are more con- 

 tracted (5'4 mm. in length). The tentacles are about 4 mm. in 

 length, and while some show two rows of pinnules with perfect 

 clearness, others show three rows equally distinct. The numbei- 

 of pinnules in a row varies from 12-15. 



In the body of the polyp and on the tentacles the spicules are 

 closely packed, thus giving a granular glistening appearance to 

 the polyp. The spicules are 0*05 mm. in length, and seem to be 

 identical with those above described. 



Locality, Wasin, British East Africa. 



Clavularia GARCiiE Hickson, var. inermis, nov. 



The polyps, which rise from a membranous stolon to a height 

 of 9 mm., are marked by annulations and also by longitudinal 

 lines. The tentacles are long and pointed, from 3-3"5 mm. in 

 length by 0'8 mm. in breadth at their proximal end. The pinnules 

 are arranged in three rows on each side, in the outer row they 

 may vai'}^ from 19-23 in number. They leave a free space on 

 both the oral and the aboral surface. In some polyps we found no 

 trace of spicules ; in others we found a few small rods. There are 

 crowded zoochlor elite. 



