CALCAREOUS SPONGES—DENDY. , 13 
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numerous very slender oxea (trichoxea) arranged radially in bundles in the chamber 
layer and sometimes projecting from the surface. One fragment shows a fair number 
of microxea, not impossibly derived from a Leucosolenia in the same tube, or possibly 
young forms of the large oxea (?). Microxea seem to be absent from the type. The 
large oxea are very distinctly flattened and show very clearly the difference in 
refringence, according to the point of view, to which I have referred in the case of 
Leucosolenia botryoides var. macquariensis and Leucetta macMariensis. 
The same uncertainty exists as to the locality of these specimens as in the case 
of Grantia cirrata var. aurorae. The type of the species was obtained at Kerguelen. 
Register Nos., Locality, &c .—IV, 5-7, ? Station II (lat., S. 66° 55'; long., E. 
195° 21'). 
Leucandra mawsoni n. sp. 
(Plate I, figs. 5, lOu-lOd). 
The single specimen in the collection (fig. 5) is an elongated sac-shaped sponge, 
strongly compressed laterally and with a single terminal vent. The shape is somewhat 
irregular, the lateral margins growing out here and there into lobose projections which 
look like incipient buds, but there is only one vent, and the sponge may be regarded 
as consisting of a single leucon individual. It is contracted below to an ill-defined, 
stout, but compressed stalk, whereby it is attached to a pebble; it also diminishes 
gradually in breadth upwards to the wide vent. The dermal surface is smooth but 
slightly uneven, and appears very minutely reticulate under a pocket lens. The vent 
is naked, without any distinct collar but with a very narrow, thin margin. The specimen 
is large for a solitary calcareous sponge, measuring about 87 mm. in height, with a 
maximum breadth of about 27 mm. (where one of the marginal lobes comes off) and a 
thickness of only about 3 to 4 mm. The vent measures about 6 mm. in long diameter 
and leads into a wide central gastral cavity. The walls of this cavity are only about 
1-5 to 2 mm. in thickness and almost touch one another, being in fact bolted together 
here and there by trabeculae formed from the lining of the gastral cavity. The gastral 
surface is smooth but uneven, with the rather wide openings of the exhalant canals 
sparsely scattered over it. The colour in spirit is pale yellowish-grey, the texture firm 
but flexible. 
The skeleton is rather feebly developed, owing to the fact that the spicules, 
though very numerous, are slender-rayed. That of the chamber layer consists of 
regular triradiates, with long and very slender rays, quite irregularly scattered between 
the flagellate chambers. That of the thin gastral cortex consists of similar spicules 
lying tangentially and rarely with a feebly developed apical ray. The dermal cortex 
is also thin, but its skeleton is fairly dense and consists of somewhat stouter triradiates, 
lying tangentially; occasionally the spicule is turned so that one ray dips down into 
the chamber layer, but I do not think that any importance need be attributed to this 
•condition. 
