Miss J. Sollas on Haddonella Topsenti. 557 
thighs granular. Grey above, with six dark brown longi- 
tudinal stripes, the median pair narrowly separated; a dark 
brown canthal streak ; limbs with regular dark brown cross- 
bars ; lower parts white. 
From snout to vent 46 millim. 
A single female specimen from McCarthy Island, Gambia, 
presented by Mr. J. S. Budgett. 
In form and markings this frog bears a remarkable simi- 
larity to Cassina senegalensis, D. & B., from which it is, 
however, easily distinguished by the terminal disks of the 
digits and the presence of a short web between the toes. 
LV.—On Haddonella Topsenti, gen. et sp. n., the Structure 
and Development of its Pithed Fibres. By IGERNA SOLLAS. 
[Plates XXVIII. & XXIX.] 
OwinG to the kindness of Dr. Harmer I have had the oppor- 
tunity of looking through a collection of corals and sponges 
brought home by Dr. Haddon from Torres Straits. Amongst 
these was a single specimen of a ceratose sponge belonging 
to the Dendroceratina. 
The sponge has been torn away from its earliest support, 
but remains attached to a piece of coral to which its distal 
parts have secondarily adhered. ‘The proximal ends of the 
fibres project from the flesh, which has been dragged away 
from them ; they are flattened and disk-like. The surtace of 
the sponge is raised into conuli, which are widely separated 
at unequal distances from one another; a little below the 
summit of each the fibre which supports it can be seen through 
the flesh as a dark line. ‘The general colour is a dull grey, 
tinged with pink (in spirit). 
The oscula are covered by a sieve-like membrane. I prefer 
this method of stating the facts to saying that “ the oscula 
occur in groups,” seeing that each group of apertures 
leads into a single continuous cavity. The dermal ostia occur 
in patches, separated from one another by anastomosing 
strands of fibrous tissue, in close contact with the dermal 
membrane. ‘The whole sponge is very cavernous. A six- 
rayed Ophiuroid was found in one of the internal passages. 
‘The flagellated chambers measure about ‘07 x ‘04 mm. on 
an average and are elliptical in form, with wide mouths 
opening directly into the excurrent canals. 
