TKTltAXONIDA. 29 



Several osciilcs aliuut ( J mm. in diameter occur along the margin ; they arc slightly 

 raised and with a thin plain rim with special spicular armature. The pores occupy 

 irregular oval areas about 2 mm. in diameter. The spicules resemble those of 

 specimen No. 421 described by Topscut, the dimensions being as follows : The amphi- 

 tyles 26G X 10 /M ; acanthostyles spined at the head and near the point, 447 X 1G /x ; 

 larger auisochcles 36 fj. long, a smaller kind 20 M long ; bipocilla 9 '75 n long, usually 

 with one end pocillate and the other flattened and with three to five minute denticles. 



An interesting feature is the presence of embryos '25 mm. in diameter with a 

 solid cylindrical core of peculiar spiued amphityles 105 x 5/ reaching from surface to 

 centre, and with anisocheles with a spine at the small end, 15*9 M long and arranged 

 in rosettes, the latter being distributed around the summit of the spicular plug or 

 cylinder. 



Specimens were obtained from (l) Winter Quarters No. 12 hole, -J5-30 fms. ; 

 (2) East end of Barrier, 100 fms. ; (3) No. 5, Seal Hole, 178 fms. ; (4) From near the 

 ship, February 28, 1902 ; (5) Off Coalman Island, 100 fms. 



The 'Belgica' collected specimens from Lat. 71 14' S., Long. 89 14' W., 

 450 metres, and from Lat. 7119'S., Long. 87 37' S., 450 metres. 



lOPHON SPATULATDS. 



(Plate XXL, tigs. 5, 5a-c, and Plate XXV., fig. 5a-d.) 

 l!>i>7. lophon spatulatlts Kirkpatrick (10a. p. 27(1). 



Sponge slender, cylindrical, branched. Colour, pale brown in spirit. Oscnles 

 oval, about 1 x G mm. in diameter, slightly raised ; surrounded by a radiating zone of 

 tyles. Pores in sieve-like areas 2-3 mm. in length and about 2 mm. in breadth, on 

 a level with the general surface. 



Flagellated chambers 26 x 23 p. 



Skeleton. Dermal ; a closely packed layer of dermal amphityles. 



Choanosomal, a loose network of 3-6 spicules thick, forming the core of the 

 cylinder; multispicular fibres, giving off strands at right angles; the longitudinal 

 fibres are joined obliquely or transversely by fibres one or two spicules thick, which 

 support the dermal membrane. 



Spicules. Megascleres, smooth styles, 462 x 25 /*, with a mucro at the basal end. 

 Ectosomal sub-amphityles 225 X 12'5/u,, fusiform with the swelled ends smooth 

 laterally, and with the extremities only slightly convex, in fact almost truncate, and 

 covered with spines. 



Microscleres. Palmate anisochelae 18"7/u long, G'2^ broad (front view). 



Bipocilla, rare, 13'6/i long, I'l5fj. thick, shaft deeply curved, slightly twined, 

 and with ends almost similar, spatulate, with crenulated edges; occasionally with live 

 relatively large denticles in place of the finer crenulation. A second kind of 

 bipocilla have a longer, less curved shaft with scoop-like rather than spathulate 



