PORIFERA OF THE L.M.B.C. DISTRICT. 165 
specimen of Raspailia viminalis do not leave any doubt 
that in a living state the spicules do project beyond the 
ectoderm. ‘These projecting bundles of styli consist, in 
most cases, of one large stylus surrounded by a number 
of small ones. In some cases the bundles consist only of 
small styli, and lastly the large styli are also found singly. 
All those different arrangements are represented in the 
semi-diagrammatic figure (Pl. V., fig. 4). The spined styli 
are found scattered throughout the whole mass of the 
Choanosome. 
Raspailia stelligera, Schmidt (Pl. V., fig. 1). 
Dictyocylindrus stuposus, Bowerbank. 
As Mr. Higgin states, this species has already been 
collected at Port Erin, Holyhead and isle of Man. On 
the 16th and 17th of February last, Professor Herdman 
obtained a number of bright orange coloured sponges at 
extreme low tide, under one of the ledges of rock, on 
the north end of Puffin Island, near the Biological Station. 
The specimens showed a narrow base and an expanded 
distal portion with more or less numerous short branches. 
The whole mass was beset with rough ridges, and spicules 
were seen projecting through the ectoderm. The height 
of the sponge-masses varied between 2 cm. and 4 cm. 
Transverse and longitudinal sections through this sponge 
show that the arrangement of the megasclera is here the 
same as in Raspailia viminalis. The only remarkable 
point is the great masses of ceratose in which the bases of 
the spicules, especially of those in the interior, are 
imbedded. The bundles of the projecting spicules consist 
of styli, and the centre of these bundles is commonly 
formed by one or more shorter and stouter styli (0°92 mm. 
by 0°012 mm.), which are surrounded by long and thin 
styli (0°8—1°5 mm. by 0°0043 mm.). The spicules of the 
