466 Rev. T. Hincks on the 
side six or seven rather tall, straight, acuminate spines, which 
slope inwards without meeting. The spines are at best a 
somewhat variable character; and the single specimen which 
MacGillivray examined can hardly be accepted as fixing the 
normal armature of his species. The general character and 
the remarkable avicularium are the same in both forms. 
Virago Sound. [Victoria (MacGillivray).| 
Membranipora echinus, n. sp. (Pl. XIX. fig. 5.) 
Zoecia quincuncial, oval, distinct, separated by rather deep 
and wide interspaces; front wall wholly membranous ; two 
spines at the top and from seven to eight slender, closely set, 
pointed, and rather tall spines down each side, which slant 
inwards but barely meet in the centre; on each side, springing 
from behind the second spine from the top, a pedicellate avicu- 
larium, the upper part large and much swollen (closely re- 
sembling a “bird’s head”’), very slightly hooked at the 
extremity, borne on a very thin pedicle; mandible slender, 
pointed. Occium (?). 
Loc. Houston Stewart Channel; Cumshewa, 20 fms. 
A very marked characteristic of this species (which belongs 
to the WM. spinifera section) is the distinctness of the zocecia, 
which lie so much apart from one another that the whole cell 
to its very base is visible, the wall flanging outward slightly 
below. It is very common amongst the dredgings. 
Membranipora exilis,n. sp. (Pl. XX. fig. 1.) 
Zoecia very regularly quincuncial, oblong, slightly en- 
larged about themiddle, subtruncate above and below, setclosely 
together, of considerable size and delicate half membrana- 
ceous material ; margin thin, a good deal raised, the front wall 
wholly membranous ; at the top of the cell two pointed spines, 
and (usually) two on one side and three on the other situated 
in the upper half of the cell, slender, acuminate, erect, jomted 
to a tubular base; a sessile avicularzum on the margin at one 
side (often wanting) just below the top; beak much swollen 
below, inclined upwards, scarcely bent at the , extremity ; 
mandible blunt, directed downwards. Occium (?). 
Loc. Houston Stewart Channel, enveloping Cellariaborealis, 
Busk, with a very thin crust. 
Membranipora Sophie, Busk, form matura. 
(Pl. XX. fig. 2.) 
Zoeciaoval, quincuncial, set very closely together; front wall 
