1908.] 



AFRICAN CALCAREOUS SPONGES. 



443 



Sycon ampullum, 



Sycandra ampulla H. 



One small specimen of this species was dredged in 6-8 fathoms 

 at Wasin. It is 11 mm. long x 5 mm. diameter. Its structure 

 is typical of the genus. The spicules are too small for Sycon 

 raphanus, and there are none of the thin su.bgastral tri- and 

 quadriradiates which are the most characteristic features of that 

 species. Comparing it with Sycon anipulktm the spicules are 

 rather thicker than the dimensions given by Haeckel and the 

 oxea are also rather longer, but on the whole it agrees fairly well. 



Sycon munitum, sp. n. (Text-fig. 91.) 



Three specimens of this new species were dredged in 7 fathoms 

 in the Zanzibar Channel. In external appearance they resemble 

 small specimens of Sycon ciliatum. Their dimensions are 

 7x3 mm., 5x3 mm., and 3x1 mm. 



The peculiarity of the species is the presence of quadriradiates 

 in the articulated tubar skeleton. Only a few species of Sycon are 

 known with quadriradiates in this position ; from these the new 

 species is differentiated by having two sorts of gastral quadri- 

 radiates, viz., small quadriradiates with short apical rays and 

 larger ones with very large apical rays. 



Text-fig. 91. 



Si/con munitum, sp. n., spicules. X 110. 

 (For explanation of the letters see text p. 444.) 



Skeleton. — The gastral skeleton is a dense felt of small tri- and 

 quadriradiates, fairly regularly arranged round the apopyles, with 

 the basal rays aborally directed and the small apical rays pro- 



