1910. | Pharetronid Sponge from Christmas Island. 127 
skeletal network entirely devoid of spicules, but the surface of the sponge 
is covered with a dermal armour of large calcareous scales. 
I propose to name the genus and species Murrayona* phanolepis,+ and to 
place them in a new sub-family Murrayonine below and next to the 
Lithonine. 
Description of Murrayona phanolepis, gen. e sp. nov. 
The specimens are in the form of smali pear-shaped or massive stony 
nodules, either sessile or with a very short thick stem, and are attached by a 
flat expanded base to the rock. Two of the specimens are complete 
(Plate 10, figs. 3, 3a), and the other two (Plate 10, figs. 1, 2) macerated 
out and devoid of both a dermal layer and of soft tissues. The largest 
is about the size of a small Barcelona nut (Plate 10, fig. 2). 
The best preserved specimen, A, has been kept entire, and the second 
complete specimen used up for sections of soft tissues and skeleton. 
Specimen A (Plate 10, figs. 3, 34, 3B) is in the form of a minute, pear- 
shaped nodule, 8 mm. high and 7 mm. broad, with a very short thick steni 
1 mm. high and 2 mm. in diameter, expanding below into a flattened 
disc of attachment. The colour is pale yellow, and the surface glistening. 
Under a lens an areolated pattern, formed by imbricating scales, can be seen. 
A little to one side of the summit is a small oscule about 0°4 mm. in 
diameter, and above the middle of the opposite aspect is an equatorial groove 
(figs. 3A, 3B) extending a little more than half-way round the sponge. Besides 
the oscule and pores of this poral groove there are no other openings into the 
sponge, the rest of the surface being covered with an impenetrable coat of 
scales (fig. 3B). 
The edges of the scales are free, that is to say there is no continuous 
membrane passing from edge to edge. Beneath the semi-translucent layer of 
scales can be seen, under a low power, the more or less parallel edges of the 
surface-lamelle of the main skeletal framework, which form supporting 
beams to the roof of scales ; and here and there between the scales and main 
skeleton very minute triradiate and tuning-fork spicules are visible. The 
poral groove shows a network of small meshes formed by bundles of 
triradiates. 
The canal-system belongs to the leuconoid type. The pores are limited to 
a groove situated on one side of the sponge about midway between the 
summit and base (Plate 10, fig. 3B). The groove, which is about 8 mm. long, 
* In honour of Sir John Murray, K.C.B., F.R.S., who has made a very generous 
donation towards-the expenses of a small dredging expedition to Christmas Island. 
t+ haves, bright, glistening; emis, scale. 
Tipe 
