1906.] ALCYONAKIANS FROM ZANZIBAR. 423 



vary from 0'8 to 1 mm. in length and have an average diameter 

 of 0"1 mm. They are straight warty spindles. Covering the 

 anthocodife there are niimerous small spindles arranged in doul:»le 

 rows ; the average dimensions are 0*5 mm. in length and 0'06 mm. 

 in breadth. There are also minute spicules on the tentacles, 

 hoi'izontally disposed in two rows. 



A prominent feature is that the general ccenencliyma bears very 

 large transversely-disposed spindles, which give it a wrinkled 

 appearance. The following measurements in millims. were taken : — 

 2-6 X 0-2, 2-4 X 0-19, 1-6 X 0-16, and l-4x0-15. No other forms 

 of spicules were to be found in the colony. 



This species should be referred to a position near iV. digitata 

 Kiikenthal. 



Locality. Wasin Channel, 10 fathoms. 



Spongodes hemprichii Klunzinger. 



A form closely resembling this species, but the spicules are not 

 red. The trunk has a leathery and rigid character and is rough 

 in appearance, the larger spicules being easily seen. At its lower 

 end it gives ofi' a number of rhizoid-like offshoots, by means of 

 which it is anchored in the sand. The colour in spirits is 

 yellowish white, but in the living colony was a weak chocolate. 

 One colony is 7 centims. in height, 6 in breadth, and 2*5 in 

 thickness, while the corresponding measurements for another are 

 5, 7, and 3"5 centims. The stem divides almost immediately into 

 three chief divisions, which bear numerous conical lobes densely 

 covered with polyps. 



In architecture the polyps agree closely with the description given 

 by Kiikenthal of *S'. {Dendronephthya) hemijvichii. Each double 

 row of spicules on the anthocodia consists of four to six pairs, but 

 five seems to be the commonest number. We cannot attach much 

 importance to the fact that the spicules are not red as they are in 

 the type, for the colour of the spicules in Spongodes is often 

 variable. In S. kUkenthali, sp. n., we found red, yellow, orange, 

 and colourless spicules. The spicules are long spindles, either 

 straight or curved, and covered with numerous rough spines which 

 are often branched. Their measurements, length by breadth in 

 millims., are as follows: — 



Stiitzbiindel spicules : 2-2 x 0-14 ; 2-4 x 0-15. 



Other spicules : 2-6 x 0-18; 2-2 x 0-14; 2-3 x 0-15; 0-3 x 0-03. 



Locality. Wasin Channel, 10 fathoms; very common at lowest 

 tides and below. Previously recorded from the Red Sea. 



Spongodes crosslandi, sp. n. (Plate XXVIII. fig. 2.) 



A complete small colony of apparently divaricate type, 13 mm. 

 in height by 12 mm. in breadth and 7 mm. in thickness. A short 

 trunk gives off three main branches, which redivide and finally 

 bear the polyps in bundles of 6-10, though a few also occur 

 singly. The general colour of the svirface is warm orange, but the 

 anthocodise and tentacles are covered with chalky- white spicules. 



