846 DR. G. J. HINDE ON RECEPTACULITIDZ. 
1880. Polygonospherites rhombifer, F. Romer, Leth. Pal. 1 Th. 
p. 298. 
The figured type is a deep cup-shaped specimen, probably imper- 
fect. The spicular plates are for the most part rhomboidal, and this 
feature would exclude it from Spherospongia. The generic position 
must remain uncertain until its interior characters have been ascer- 
tained. 
Distribution. Upper Devonian: Harz, Germany. 
Species which have been erroneously referred to Receptaculites. 
Receptaculites ? elegantulus, Billings, Pal. Foss. Can. vol. i. p. 359, 
f. 347. The only characters shown are faint ridges arranged in 
quincunx, marking out small rhomboidal pits. The small propor- 
tions and uniform size of these interspaces appear to me to indicate 
that it does not belong to the present group. 
Receptaculites? insularis, Billings, Cat. Silurian Fossils of Anti- 
costi, p. 29. Billings recognizes that the characters of this species 
are altogether distinct from those of the genus under which he has 
placed it with a query, and he suggests that it is congeneric with 
Tetragonis sulcata, Kichw. Leth. Rossica, p. 432, t. 27. f. 5a, 6. 
But this latter species is not a true Tetragons, and probably belongs 
to a quite distinct group. 
Nore.—S. A. Miller, in Cat. American Pal. Fossils (1877), refers 
to Receptaculites, Lunulites dactioloides, Owen, 1840, and Orbituloides 
reticulata, Owen, 1840, ‘ Report on Mineral Lands, Niagara Group.’ 
I have been unable to find this work in the libraries of the scientific 
societies in Londen, nor does it appear to be quoted in the ‘ Biblio- 
graphy of North American Invertebrate Paleontology, White and 
Nicholson. F. Romer, in Leth. Pal. 1 Th. p. 289, 290, refers the 
above species to Miller himselt! 
In the supplement to the Catalogue (1883) Miller further refers 
to Receptaculites sacculus, Hall, ‘ Descriptions of new Species of Fossils 
from Waldron, Indiana,’ 1879, and Receptaculites devonicus, Whit- 
field, ‘ Descriptions of new Species of Fossils from Ohio,’ 1882. 
Neither of the papers containing these descriptions is obtainable in 
London, nor can I ascertain where they have been published. 
EXPLANATION OF PLATES XXXVI. & XXXVI. 
Puate XXXVI. 
Figures 1, 1 a-o. Ischadites Kenigti, Murchison. 
Figs. 1, la-c. Specimens showing differences in form and conditions of preser- 
vation. All natural size. 
1. A small form, showing a prominently developed central zone, and with 
the summit-plates of the spicules preserved. 
1a. A specimen with an elevated summit, and clearly showing the hori- 
zontal rays of the spicules, the summit-plates which originally 
covered the surface having disappeared. 
