with descriptions of some new genera. 403 
inosculating in every direction without order. Fibre solid, cylin- 
drical, without spicula, with the exception of a few large com- 
pressed fibres, which contain them in the centre. Investing 
membrane thin, pellucid and simple. Interstitial substance ge- 
latinous, containing siliceous spicula. 
There are many of the Spongiade which approach very closely 
to the true Spongia in the external appearance of the skeleton 
and in many of the prominent generic characters, but which 
nevertheless vary in their structural peculiarities in so marked 
and decided a manner as to render it advisable to arrange them 
in other genera, and foremost among these stands the group of 
which Spongia fistularis, Lamarck, is the type, and which I pro- 
posed in my former paper to make the type of a new genus, and 
to designate it Fistularia; but upon reconsideration I find, that 
although a most appropriate designation for the proposed genus, 
it has already been apphed as a generic term in botany, so that it 
were better to abandon it altogether and to adopt another name, 
which, although it may not be so expressive of the leading cha- 
racter of the genus, will be more distinctive as regards other ge- 
nera; and as I have been in a great measure indebted to my 
friend Dr. Veronge for a correct knowledge of this very inter- 
esting natural group of the Spongiade in the condition in which 
they exist in their native element, I shall be domg but an act of 
justice in commemorating his exertions in the cause of science by 
naming it in honour of him, and the following I propose as the 
characters of the genus 
VERONGIA. 
Gen. Char. Skeleton composed of a network of keratose fibres 
inosculating im every direction without order. Fibre cylindrical, 
continuously fistular, without spicula. Cavity of the fibre simple. 
The external character of the fibre of this group is widely dif- 
ferent from that of the great mass of the true Spongia. While 
in the latter they are usually flexible, fine in texture, and of a 
colour approaching to light amber ; in the former, on the con- 
trary, the fibre is rigid, coarse in texture, and very deeply co- 
loured. The great central cay ity of the fibre usually occupies 
about one-third of its diameter, but in some species it 1s of much 
larger dimensions. It is generally nearly uniform in its size in 
all parts of the same species, but occasionally it dilates consider- 
ably for a short space and then resumes its original diameter. It 
is also usually somewhat increased in its dimensions at the ana- 
stomosing portion of the fibre, as shown in PI. XIII. fig. 7, which 
represents a piece of the fibre at one of the anastomosing points, 
seen with a power of 100 linear. 
The great central cavity is lmed with a thin pellucid mem- 
