442 



MK. C. F. JENKIN ON 



[May 12, 



same len^h, but those of the smaller quadriradiates are often of 

 unequal lengths. The oscules of both tubes are too much damaged 

 to furnish any indication of their structure. 



Text-fig. 90. 



Leucosolenia irregtdaris, spicules. X 110. 

 (For explanation of the letters see text below.) 



Spicules (text-fig. 90). 



The oxea are of one sort : — 



(a) Nearly straight oxea sharply pointed at both ends, 300- 

 800 n long X 16-28 /x thick ; the usual thickness is 21-24 yu. 



The quadriradiates are of two sorts : — 



(6) Large quadriradiates. Facial rays approximately regular, 

 150-220 /x long X 20 /Lt thick. Apical rays usually slightly bent 

 near the point, 210-260 /u long x 16-20 // thick. 



(c) Small quadriradiates. Facial rays usually regular, occasion- 

 ally of unequal lengths, 100-200 // long x 10-16 ;u thick. Apical 

 rays very slender and sharply pointed, always bent near the point, 

 120-150 n long x 7 /i thick. 



Sycon ciliatum Fab. 



Sycandra ciliata H. 



Two small specimens of this species were dredged in 7 fathoms 

 in the Zanzibar Channel. Their dimensions are 8x2 mm. and 

 5x I5 mm. 



