34 
188. 
189. 
190. 
BRITISH FOSSIL SPONGES. 
chilleum, Aulocopium, Astreospongia, Protospongia, and Acanthospongia; and 
references are given to the species described. Brachiospongia, Acestra, 
Bothroconus, and some other genera are regarded as doubtful. 
. 1881 Sortas, W. J. On Astroconia Granti, a new Lyssakine Hexactinellid 
from the Silurian Formation of Canada (Quart. Jowrn. Geol. Soc., 
vol. xxxvil, pp. 254—260, figs. 1—11). 
Describes various forms of detached acerate and hexactinellid spicules, 
which are referred to this new genus and species. 
. 1881 Sorzas, W. J. Note on the Occurrence of Sponge-Spicules in Chert 
from the Carboniferous Limestone of Ireland (Ann. and Mag. Nat. 
Hist., vol. vii, pp. 141—148, fig. 1). 
Mentions the occurrence, in some cases in great abundance, of spicules in 
microscopic sections of chert, which had been described by Prof. Hull as of 
inorganic origin. 
1881 Warrrienp, R. P. Observations on the Structure of Dictyophyton 
and its Affinities with certain Sponges (American Journ. of Science, 
vol. xxii, pp. 53, 132). 
The structure of this organism, which had been referred by Hall to Alga, 
is compared to that of the recent Auplectella, and it is supposed to have con- 
sisted of siliceous fibres, although positive evidence for this is at present 
wanting. 
In a subsequent note an example of Uphantenia is described, in which the 
spicules forming the longitudinal and transverse bundles are now preserved in 
the condition of pyrite, and the rectangular spaces between the bundles are 
also covered with a thin film of the same substance. 
1880 NicHonson and Ernerrpcr, Junr. A Monograph of the Silurian Fossils 
of the Girvan District. 
A description is given of Ischadites Kanigii, Murch. ; its systematic posi- 
tion is regarded as doubtful ; the siliceous rope of a Sponge is described under 
the name of Hyalonema (?) Girvanense (p. 239, Pl. xix, figs. 1, 1 8). 
1881 Wuitrienp, R. P. Remarks on Dictyophyton and descriptions of new 
species of allied forms from the Keokuk Beds at Crawfordsville, 
Indiana (Bulletin No. 1, American Mus. Nat. Hist., p. 10, Pls. 3, 4). 
Refers to the different names applied to this genus from time to time, and 
gives detailed descriptions of species of Uphantenia and Dictyophyton. The 
structure is stated to consist of longitudinal and transverse fibres or threads, 
formed of bundles of cylindrical spicula. 
