60 THE PALEONTOLOGY OP MINNESOTA. 



(.Synopsis of Rereptaoulites. 



R. OALCIFEKU8 Billings. 



3865. Beceptaculites caldferus BILLINGS. Paheozoic Fossils, vol. i, p. 359, fig. 346; p. 384, flg. 358. 

 1865. Beceptaculites cakiferus BILLINGS. Canadian Naturalist and Geologist, sec. ser. vol. ii, p. 190, fig. t>. 

 1884. Beceptaculites caldferus HINDE. Quart. Jour. Geol. Soc. London, vol. xl, p. 845. 

 This is the oldest known species of the genus. 



Formation ami locality .Ca.\citerous formation ; Mlngan islands, Lower St. Lawrence. 



R. MAMMILLAKIS WttlcOtt . 



1884. Receptaculites mammillaris WALCOTT. Monograph U.S. Geological Survey, vol. viii, p. 65, pi. 



11, flg. 11. 



This species is smaller than It. occidental Salter, and has the outer margin elevated, producing a 

 broad, deep depression in the upper portion. 



Formation ami local ft u.~ Upper part of the Pogonip group =C'ha/.y group of New York ; Eureka and White Pine districts. 

 Nevada. 



R. ELONGATUS Wakott. , 



1884. Seceptaculites elongatiis WALCOTT. Monograph U. S. Geological Survey, vol. viii, p. 66. 

 A cylindro-conical species, with a very deep depression on the upper side. The largest head-plates 

 of the spicules are 1 mm. in width by flve-sixths of 1 mm. in length. 



Formation andlocnJiti/.-Upper part of the Pogonip group- Cha/.y group of New York; Eureka district, and in the 

 Pahranagat range, Nevada. 



R. ELLIPTICUS Wakott. 



1884. Seceptaculites ellipticus WALCOTT. Monograph U. S. Geological Survey, vol. viii, p. 67, pi. 11 



flg.. 12. 



Seems to differ from B. elongatus in having larger spicular head-plates. The curved form and ellip- 

 tical transverse section may be due to accidental causes. 



Formation and locality. Upper part of the Pogonip group= Chazy group of New York ; Eureka district, Nevada. 



R. OCCIDENTALS Salter. 



?1847. Beceptaculites neptuni HALL; (non Def ranee). Paleontology of New York, vol. i, p. 68, pi. 24, 



flgs. 3a-3d. 



?1855. Beceptaculites neptuni EMMONS. American Geology, pt. ii, p. 230, pi. 14, flg. 1. 

 1859. Beceptaculites occidentalis SALTEK. Canadian Organic Remains, dec. i, p. 45, pi. 10, flgs. 1-7. 

 1863. Beceptaculites occidentalis BILLINGS. Geology of Canada, p. 937. 

 1865. Receptaculites occidentalis BILLINGS. Paleozoic Fossils, vol. i, p. 381, flgs. 354-356. 

 1865. Receptaculites occidentalis BILLINGS. Canadian Naturalist and Geologist, sec. ser., vol. ii, p. 



187, flgs. 2-4. 

 1884. Beceptaculites occidentalis HINDE. Quar. Jour. Geol. Soc. London, vol. xl, p. 842, pi. 37, flgs. 



3a-3m. 



Very similar to B. oweni, but it differs in having a greater number of canals in the plates of 

 the upper or Inner surface; also in the head-plates of the outer or under surface having prominent central 

 knobs. 



Formation and locality. Trenton limestone; Pauquette Rapids, Ottawa river, Canada; two miles south of High 

 Bridge, Kentucky; and ? Carlisle, Pennsylvania. 



I!. INFUNDIBULIFORMIS EalOU, sp. 



1832. Coscinopora infundibuliformis EATON. Geological Text Book. 



1863. Receptaculites infundibuliformis HALL. Sixteenth Rep. N. Y. State Cab. Nat. Hist., p. 67. 

 1883. Beceptaculites infundibuliformis HALL. Second Ann. Rep. N. Y. State Geologist, pi. 23, flg. 10. 

 ?1883. Beceptaculites monticulatus HALL. Ibidem, pi. 23, flgs. 3-9, 11. 

 1887. Beceptaculites infundibuliformis HALL. Palaeontology of New York, vol. vi, p. 290, pi. 24, 



flgs. 3-11. 



A large disk-shaped species much like B. occidentalis. The specimens to which the name B. monti- 

 ndatus has been given are now regarded by Prof. Hall as the young of this species and should he 

 compared with Cerionites dactylioides Owen, sp.,* of the Niagara group. 

 Formation and Locality. Lower Helderberg group; Helderberg Mts., New York. 

 *Geol. Surv. Illinois, vol. iii, p, 345, pi. 5, figs. 2a-2o: 1868. 



