Paleontology of the Ciucinmiti Croup. 



6r 



The genus Iscliaditcs is considered distinct by Hindc, but 

 some other authors place it as a synonym. 



From the Cincinnati group Mr. E. O. Ulrich has described 

 two genera, A)wmaloiiies and LcpidoUtcs, which are here con- 

 sidered as congeneric with Rcceplaciilitcs. In order that 

 others may judge, the essential features of the two genera are 

 given below. 



Auomahidcs, Ulrich, 1878: — Hollow, conical, compressed 

 bodies ; composed uniformly of elongated, c>'lindrical, spine- 

 like bodies, which are placed parallel with each other and 

 l^erpendicular to the surface. The affinities of the specimens 

 were supposed to be with the Echinodermata. (Jour. Cin. 

 Soc. Nat. Hist., vol. i, 1878, p. 92.) 



Mr. S. A. Miller places the genus with the Echinodermata, 

 and remarks that the word was constructed upon two adjec- 

 tives, and founded upon a fragment not understood. (N. Am. 

 Geol. & Palaeontology, 1889, p. 224). An article among the 

 editorial comments in the American Geologist (vol. i, 1888, p. 

 324), says, that to place Anonialoides with Reccptaculitcs "is 

 simply ridiculous." Had the waiter of that paragraph turned 

 to page 381 of Billings's Paleozoic Fossils, volume one, and 

 compared figure 354 with that given on Plate IV., figure 6 /;. 

 of vol. I of the Journal of the Cincinnati Societ}^ of Natural 

 History, he would have found some resemblance. Turning 

 to page 380 of Palaeozic Fossils, he would have read: "The 

 tubular skeleton [of Rcccptacii/itcs], above alluded to, consists 

 of numerous small, straight, rarely curved, cylindrical tubes, 

 or hollow spicula, placed parallel to each other, and at right 

 angles to the planes of the body wall, of wdiich they form the 

 greater portion." These words are almost exactly those used 

 by Mr. Ulrich in his definition of the genus. The tw'O figures 

 referred to are reproduced below for comparison. 



Kir,. 4. — a. Receptaculites (after BiUiufjs). 

 piHars of Aiiot)iaIoidi's. 



b. Anomahitdes (after Ulrich) 



