276 Mr. E. Kirkpatrick on the Monaxonellida 



219xl8"75 ytt (without including spines), larger spines 

 on the head 9 /x long. Ectosomal auiphitjles, 356xll/tt, 

 straight, very slightly fusiform, subtylote, and with a small 

 niucro at each end. Microscleres none. 



Myxilla victoriana, Dendy [Halichondria pustalosa^GiLxtQx) , 

 would come under this genus, although, at the same time, it 

 is in possession of isochelaj, and the heads of the styli of the 

 main fibres occasionally liave a slight indication of spination. 



Localities. Coulman I., 100 fath. ; east end of Barrier, 

 100 fath. 



lophon spatulatus, sp. n. 



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 /j,. 



ISkeleton. — Dermal : a closely packed layer of dermal tyles. 



Choanosomal : a loose network of multispicular fibres 

 3-6 spicules thick forms the core of the cylinder. From 

 the central core are given off at right angles fibres one or two 

 spicules thick which support the dermal membrane. 



Sjiicules. — Megascleres : smooth styles, 462x25 ju., with a 

 mucro at the basal end. Ectosomal subtyles 225 x 12'5 /*, 

 fusiform, with the swelled ends smooth laterally, and with 

 the extremities only slightly convex, in fact almost truncate, 

 and covered with spines. 



Microscleres : palmate anisochelpe 18*7 yu. long, 6'2 /a broad 

 (front view). 



Bipocilla rare, 13'6 yu, long, 1'15 fx thick, shaft deeply 

 curved, slightly twisted, and with ends almost similar, spatu- 

 late, 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 tiian spathulate ends, each scoop having four or 

 five denticles. One example has three sharp prongs at one 

 cud and the spathulate prolongation at the other. 



The species is represented by numerous small, for the most 

 part fragmentary, slender cylindrical pieces. 



Since writing the above description accounts of two new 

 species of lophon from the Antarctic have been published by 

 Topsent, viz. /. unicofnis and /. 2>luricorms. The two new 

 species described in the present Report and Topsent's two 

 species all possess the curious modified acanthostyles. 

 1. uuirurnittj Topscnl, has nc bipocilla, and I. pluricornis has 



