SPONGES, GRAPTOLITES, CORALS. 61 
Ischadites.[ 
R. BURSIFORMIS Hall. 
1863. Receptaculites catoni HALL. Sixteenth Rep. N. Y. State Cab. Nat. Hist., pp. 68, 226 (not 
defined). 
1883. Receptaculites bursiformis HALL. Second Ann. Rep. N. Y. State Geologist, pl. 238, figs, 12-14. 
1887. Ischadites bursiformis HALL. Paleontology of New York, vol. vi, p. 291, pl. 24, figs. 12-14. 
Much like R. infundibuliformis in shape, but with larger head-plates of the spicules than in that 
species. 
Formation and locality.—Schoharie grit; Albany and Schoharie counties, New York, 
R.? SAOCCULUS Hall. 
1879. Receptaculiles sacculus Hay. Transactions Albany Institute, vol. x. 
1882. Receptaculites sacculus HALL. Eleventh Rep. State Geologist of Indiana, p. 222, pl. 1, fig. 5. 
Probably this fossil does not belong to the Receptaculitide. Its nature cannot be determined from 
the description and figure given. 
Formation and Locality.—Niagara group; Waldron, Indiana. 
R.? INSULARIS Billings. 
1866. Receptaculites ?insularis BILLINGS. Catalogue Silurian Foss. Anticosti, p. 29. 
1884. Receptaculites ?insuiaris HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 846. 
‘* Probably belongs to a quite distinct group” (Hinde). 
Formation and Locality.—Anticosti group ; Anticosti. 
R.? ELEGANTULUS Billings. 
1865. Receptaculites ? elegantulus BILLINGS Paleozoic Fossils, vol. i, p. 360, fig. 347. 
1884. Receptaculites ? elegantulus HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 846. 
This does not belong to the Receptaculitide. 
_ Formation and Locality —Calciferous formation ; Mingan islands, Lower St. Lawrence. 
R.? DEVONICUS Whitfield. 
1882. Receptaculites devonicus WHITFIELD. Annals New York Acad. Sci., vol. ii, p. 198. 
1890. Receptaculites devonicus WHITFIELD. Ibidem, vol. x, p. 519, pl. vi, fig. 10. 
Probably an Ischadites. 
Formation and locality —Corniferous of Ohio. 
ISCHADITES, Murchison emende Hinde. 
PLATE F, FIGS. 5-10. 
1839. Ischadites, MURCHISON. Siluria, p. 697. 
1842. Tetragonis, EICHWALD. Urwelt Russlands, hft. ii, p. 81. : 
1852. Selenoides, OWEN. Geological Survey of Wisconsin, Iowa, and Minnesota, p. 586. 
1859. Dictyocrinus, HALL. Palwontology of New York, vol. iii, p. 135. 
1865. Receptaculites, (partim), BrLLINnes. Paleozoic Fossils, vol. i, p. 378. 
1884. Ischadites, HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 810. 
The following description is somewhat condensed from Dr. Hinde’s detailed 
diagnosis of this genus (Joc. cit. p. 811): “Outer form variable. The prevalent forms 
are ovate or biconvex; depressed conical; subspherical and pyriform. Base either 
obtusely conical, flattened or concave. Summit usually obtusely conical; rarely 
with a small central elevation. A small circular perforation is present in the center 
of the summit which opens into the originally hollow cavity of the body. [According 
to Herr Rauff, this opening is closed by a large and variable number of plates.| 
