66 
1859. 
1883. 
1887. 
1861. 
1866. 
1867. 
1870. 
1875. 
1875. 
1884. 
THE PALEONTOLOGY OF MINNESOTA. 
{Ischadites. 
I. SQUAMIFER Hall. 
e 
Dietyocrinus squamifer HALL. Paleontology of New York, vol. iii, p. 135, pl. 7A, figs. 11, 18. 
Receptaculites squamifer HALL. Second Ann. Rep. N. Y. State Geologist, pl. 23, figs. 1, 2. 
Ischadites squamifer HALL. Paleontology of New York, vol. vi, p. 291, pl. 24, figs. 1, 2. 
Formation and locality. Lower Helderberg ; Schoharie, New York. 
I, TESSELLATUS Winchell and Marcy. . 
Receptaculites infundibulum HALL.* Report of the Superintendent of the Geological Survey 
of Wisconsin, p. 16. 
Ischadites tessellatus WINCHELL and MARCY. Memoirs Boston Soc. Nat. Hist., vol. i, p. 85, 
pl. 2, fig. 3. 
Ischadites tessellatus HALL. Twentieth Rep. N. Y. State Cab. Nat. Hist., pp. 390, 395. 
Receptaculites formosus MEEK and Wor?THEN. Proc. Acad. Nat. Sci. Philadelphia, sec. ser vol 
XIV, p. 22. 
Receptaculites formosus MEEK and WoRTHEN. Geological Survey of Illinois, vol. iv, p. 500, pl. 
24, fig. 1. 
Ischadites tessellatus GiMBEL. Abhandl. der. k. bayer. Akad. der Wissensch., bd. xii, p. 40. 
Ischadites tessellatus HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 839. 
The pear-shaped form and the large spicular head-plates readily separate this from all other Amer- 
ican species of the genus, except J. canadensis Billings, which will probably prove to be a synonym. 
Formation and locality.—Niagara limestone ; near Chicago, Lllinois, and Racine, Wisconsin. 
1863. 
1865. 
1865. 
1880. 
1884. 
I. CANADENSIS Billings. 
Ischadites canadensis BILLINGs. Geology of Canada, p. 309, flg. 313, and p. 327 (not described). 
Receptaculites canadensis BILLINGS. Paleozoic Fossils, vol. i, p. 384, fig. 362 (not described). 
Receptaculites canadensis BILLINGs. Canadian Naturalist and Geologist, sec. ser. vol. ii, p. 191, 
fig. 10. 3 is 
Receptaculites canadensis RoMER. Lethzea Palaozoica, p. 289. 
Receptaculites ? canadensis HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 844. 
Probably identical with J. tessellatus, in which case this name wil] have precedence, provided, how- 
ever, that a figure without a description is regarded as sufficient for establishing a species. 
Formation and locality.—Niagara limestone ; township of Esquesing, Ontario, Canada. 
1863. 
1879. 
1882. 
1884, 
I. SUBTURBINATUS Hall. 
Receptaculites subturbinatus HALL. Transactions Albany Institute, vol. iv, p. 224. 
Receptaculites subturbinatus HALL. Twenty-eighth Rep. N. Y. State Mus. Nat. Hist., p. 103, 
pl. 3, figs. 1-3. 
Receptaculites subturbinatus HALL. Hleventh Rep. State Geologist of Indiana, p. 221, pl. 2, 
figs. 1-3. 
Ischadites koenigii (partim) HInDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 836. 
This species is regarded as a synonym of I. kenigii by Hinde (ep. cit.). 
Formation and locality.—Niagara group ; Waldron, Indiana. 
1861. 
1875. 
1882. 
1884. 
I, HEMISPHERICUS Hail. 
Receptuculites hemisphericum HALL. Report of the Superintendent of the Geological Survey 
of Wisconsin, p. 16. 
Reeeptaculites ohioensis HALL and WHITFIELD. Palxontology of Ohio, vol. ii, p. 123, pl. 6, fig. 1. 
Receptaculites hemisphericum WHITFIELD. Geology of Wisconsin, vol. iv, p. 269, pl. 13, fig. 4. 
Ischadites kenigii (partim) H1NDE. Quart. Jour. Geol. Soc. London, vol. x1, p. 836. 
This is also regarded asa synonym of J. kewnigii by Dr. Hinde. 
Formation and locality.—Niagara limestone ; Racine and Waukesha. Wisconsin, and Yellow Springs. Ohio. 
*Since this species was accompanied by a poor description, and without figures, we prefer to use the name J. tessellatus 
forit. Dr. Hinde (op. cit. p. 839) says regarding R. infundibulum, ‘in the absence of figures, mere verbal description, like 
Hall’s, of the fossils of this group is quite insufficient for the recognition of species, more particularly when the character of 
the fossil is so little understood by the author that he regards the base of the fossil as its summit, and vice versa.” Meek and 
Worthen (Geol. Survey of Illinois, vol. iii. p. 302) also say that they were unable to identify “several allied forms already 
named and described from these rocks, and not yet figured.” 
