444 MR. c. F. JENKIN ON [May 12, 



jecting iuto the gastral cavity. The apical rays being short, many 

 of them hardly reach further than just through the thick gastral 

 layer. Among these spicules, every here and there, lies one of 

 the large quadriradiates, with its large apical ray projecting far 

 into the gastral cavity. 



The articulated tuhar skeleton is built up of tri- and quadri- 

 radiates. The short apical rays of the quadriradiates project 

 into the flagellated chambers. The tops of the chambers are 

 crowned with tufts of small oxea. 



The oscule has a thick fringe of thin straight oxea. The 

 flagellated chambers get shorter near the oscule and there is no 

 collar. There are remains of a diaphragm across the oscule. 



Spicules (text-fig. 91). 



The oxea are of one sort : — 



(a) Oxea from the ends of the flagellated chambers, nearly 

 straight, pointed at both ends, 170-400 fi long X 8 /l< thick. Some 

 of these are more refringent than others. The refringent spicules 

 are quite straight. 



The triradiates are of three sorts : — 



(b) Alate triradiates from the tubar skeleton. Basal rays 

 straight, 1 1 0-1 70 ju long x 5-6 /i thick. Paired rays bent upwards, 

 60-100 ju long X 5-7 fi thick. Oral angle about 140". 



(c) Alate subgastral triradiates. Basal rays straight, 180-230 /j, 

 long X 6 ^ thick. Paired rays bent downwards, 80-1 00 yu long x 

 4-6 /.t thick. 



(d) Alate triradiates from the gasti^al layer. Basal rays straight, 

 80-210 ju long X 6-8 /x thick. Paired rays bending upwards, 

 sometimes unequal in length, 70-1 30 /x long x 6-8 //, thick. 



The quadriradiates are of three sorts : — 



(e) Alate quadriradiates from the tubar skeleton. The facial 

 rays are similar to (6) but larger. Basal rays 140-220 /x long. 

 Paired rays 70-100 /x long. Apical rays slender, slightly bent 

 near the point, 50 /a long x 3 /x thick. 



(/) Small alate quadriradiates fi-om the gastral layer, similar 

 to (d) with the addition of an apical ray 60 fx long x 6 /x thick. 



{g) Large alate quadriradiates from the gastral layer. Basal 

 rays straight, over 200 yu, long x 10 /x thick. Paired rays nearly 

 straight, 180yu, long x 9-10 /x thick. Apical ray slightly bent 

 orally, 320-380 /x long, oval in section 16 jj. deep x 8 /x thick. 



Leucandra ananas H. (Text-fig. 92.) 



Leucandra ananas H. 



One specimen of this species was dredged in 3 fathoms in 

 Chwaka Bay, Zanzibar. It is flask-shaped, 20 mm. long x 

 13 mm. diameter, with an oscule 5 mm. diameter. It was dirty 

 white in colour when alive. The body-wall is about 3 mm. thick 

 near the middle and surrounds a gastral cavity about 7 mm. 

 diameter. 



