t. W. H. ROW—-REPORT ON THE SPONGES : NON-CALCAREA. 3aL 
Spicules. (Text-fig. 14.) 
The only spicules are oxea, of varying shape 
and size, but not marked out into different 
types, as all intermediate conditions between the 
extremes can be found. 
They are very rarely quite straight, and 
sometimes very strongly curved, and not always 
regularly ; they vary considerably in length, 
and slightly in thickness in the full - grown 
specimens, but all stages of growth can be found 
in the sponge, and therefore all lengths and 
thicknesses. As a rule, those spicules which 
are very strongly bent are rather shorter than 
those which are straight. They are thickest 
in the middle and taper very slightly in each 
direction for a great part of their length ; 
the ends are of the typical irregular Axinellid 
shape and are sharply pointed. 
The length varies in apparently full-grown 
Eg odenthceanince spicules from 0°35 fm. to 0:43 mm., and the 
Spicules, x 250. thickness from 0-006 mm. to 0:01 mm. 
Family DESMACIDONIDA. 
Sigmatotetraxonida in which some of the microscleres are chelze (except 
where such have been lost by degeneration). 
Sub-Family EspereLiin®. 
Desmacidonidee without echinating spicules, and without fistular outgrowths 
of the sponge-body. 
ESPERELLA DENDYI, n. sp. (Text-fig. 15.) 
This remarkable species is represented by two specimens, one of which is 
very small. Neither is quite complete, each showing a large torn surface. 
The largest consists of a roughly triangular mass, which apparently grew in 
an upright position ; it measures 90 mm. high. The outer surface, where 
visible, is exactly like that of Hsperella murrayi, of the ‘ Challenger’ report 
(Ridley & Dendy (24)), being marked out into irregularly shaped areas by 
the peculiar meandering pore-grooves which are characteristic of these two 
