R. W. H. ROW—REPORT ON THE SPONGES : NON-CALCAREA., 319 
that were slightly curved. They are of the same diameter throughout the 
greater part of their length, and taper abruptly to a sharp point at each end. 
They measure 0°13 mm. in length and 0:005 mm. in thickness. 
Locality. Agig Harbour. 
Distribution. Red Sea. 
HALICHONDRIA BUBASTES, n. sp. (Text-fig. 11.) 
A single large specimen of this new species occurs in the collection. It 
is massive and irregular in shape, and possesses several very irregular shallow 
fistulee arising from it. It measures 75 mm. x 55 mm., and is 40 mm. 
high, including the fistule. On the summits of most of these fistulee 
are the oscula, which are large and possess a distinct oscular lip. They 
vary in size from 2 mm. to 5 mm. in diameter. The pores could not be 
distinguished. 
This external form is noteworthy as being identical with that of Trachyopsis 
halichondrioides, Dendy (11), specimens of which also occur in the Red Sea. 
Its spiculation is, however, quite different to that of Trachyopsis. 
The surface of the sponge is not reticulate, but quite even and regular ; it 
is, however, very minutely hispid through the slight projection of spicules 
from it. 
The sponge is soft and very easily compressible, but when whole is firm 
and elastic, though in spirit the interior of the sponge is friable and easily 
breaks. 
The colour is similar to that of sand. 
The skeleton arrangement is very irregular, and consists of a very ill-defined 
network of spicular fibre and scattered spicules. The number of spicules 
which lie scattered singly, or in twos and threes, about the sponge is very 
large, and they render the skeleton arrangement very similar to that of 
Remera at first sight ; but since this arrangement varies in different parts of 
the sponge, both as to the regularity of the network and the size of the mesh, 
and since the size of the spicules is also very variable indeed, I have come to 
the conclusion that the apparent regularity of the skeleton arrangement in 
some parts of the sponge is only accidental, and I have therefore placed the 
species in Halichondria rather than in Reniera. 
The spicular fibres, where they occur, vary very greatly in the number of 
spicules they contain, and also in the closeness with which their spicules are 
bound together. They cannot, however, be divided into primary and 
secondary fibres, nor do they have any definite direction in the sponge. The 
spicules composing them vary in number from 1- to 20-serial, and fibres of 
all intermediate sizes may be found. 
LINN. JOURN.—ZOOLOGY, VOL. XXXI. 26 
