TKTUAXONIDA. 29 



Several <smle8 about 9 nun. iu diameter occur along the margin ; they an slightly 

 raised atul with a thin plain rim with sjHvial spirular armature. The pores owupy 

 irregular oval aren-s about 2 mm. in diameter. The spirules resemble theme of 

 specimen No. 421 described by Topsent, the dimensions Injing as follows : The amphi- 

 t\l. _<'. i ; . 1 1. lt : iicanthustyli's -|.iii.-.i ,-ii the !I<M.J tad ai u tlu point, i ir < L6ji 

 larger anisoeheles 36 p long, a smaller kind 20 M loug ; bipocilla 9*75 M long, usually 

 \\iili 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 coreof peculiar spiued amphityles 105 x 5/u reaching from surface to 

 ' nitre, 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, 25-30 fins. ; 

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

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



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

 450 metres, and from Lat 71 19' S., Long. 87 37' S., 450 metres. 







lOPHON 8PATULATD8. 



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

 1907. lophon spaJttlatiis Kirkpatrick (lOa. p. 276). 



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

 oval, about 1 x 6 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 ft. ' 



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 ft, with a mucro at the I M-M I end. 

 Ectosomal sub-amphityles 225 x 12 '5 ft, fusiform with the swelled ends smooth 

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

 covered with spines. 



Microscleres. Palmate anisochelee 18 7 ft long, 6 2 p. broad (front view). 



Bipocilla, rare, IS '6 ft long, I '15 ft thick, shaft deeply curved, slightly twisted, 

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

 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 spathulatc 



