DR. G. J. HINDE ON RECEPTACULITIDZ. 797 
dently erroneously, from the Jura-Kalk, probably from Switzerland. 
The condition of these specimens appears to have been similar to 
that of Defrance’s types in having the places occupied by the 
connecting pillars vacant; and this fact apparently led Goldfuss to 
compare the tubes to the canals in the siliceous sponge Coscinopora 
infundibuliformis, Goldf. 
Murchison, in the ‘Silurian System’ (1839), p. 697, pl. xxvi. f. 11, 
under the name of Jschadites Keenigii, figures a group of fossils on 
the surface of a slab of shaly limestone from Lower Ludlow rocks 
at Ludlow. Though the specimens have all been compressed, and 
the original structure entirely removed, leaving merely impressious 
of its former presence, yet the originally ovate or subspherical form 
and the tessellation of the surface can be clearly recognized. Mur- 
chison, without expressing an opinion as to the affinities of these 
fossils, referred them to Mr. Konig, who thought that they might 
belong to the family of Ascidiz. No suspicion of any relationship 
between these ovate bodies and the cup- and disk-shaped specimens 
of Receptaculites appears to have been entertained. 
Professor Phillips, in the ‘ Paleozoic Fossils of Devon and Corn- 
wall’ (1841), p. 185, t. 59, f. 49, first named the type of another 
genus of this group, Spheronites tessellatus, The type specimen 
had, indeed, been already figured nine years previously, in connexion 
with a paper by De la Beche ‘On the Geology of Tor and Babbicombe 
Bays, Devonshire”*, though it had not been named; but Mr. W. J. 
Broderip, to whom it had been referred, stated that the fossil may 
have belonged to the Tunicata. The specimen is pear-shaped, par- 
tially imbedded in a hard limestone, and showing a surface of hexa- 
gonal plates. Phillips regarded it as a Cystidean, allied to the genus 
Echinospherites, Wahlenberg, and he placed it in the Cystidean genus 
Spheronites, Hisinger. 
In 1840, Eichwald, in ‘Die Urwelt Russlands,’ p. 81, t. 3, 
f. 18, proposed the genus Tetrayonis for a fossil of uncertain origin, 
which he thought might probably belong to the same family as the 
problematical IJschadites, Murch. Curiously enough, Hichwald’s 
type specimen was brought to London by Murchison to show to 
W. Lonsdale; but that paleontologist does not appear to have 
recognized any relationship between it and Ischadvtes, though, as 
we shall see later on, it is undoubtedly congeneric with this latter 
genus. Thespecimen is pear-shaped, and the outer surface is divided 
by vertical and transverse lines into oblong areas, with small per- 
forations at the alternate angles. Oblique lines regularly winding 
round the fossil are also mentioned. I shall show further on that 
the appearances presented by the type of Tetragonis are similar to 
those of [schadites, when the rhomboidal surface plates are removed 
and the horizontal spicular rays beneath are exposed. This being 
the case, Eichwald’s name Z’etragons will have to give place to Mur- 
chison’s name Jschadites, which has the priority. Eichwald ranks 
Tetragonis with corals, and in this order he also places another 
example of [schadites which is named Receptaculites Bronnit. 
* Trans. Geol. Soc. ser. 2, vol. iii. p. 164, t. 20. figs. 1, 2. 
