59 



very nearly allied to" A. Orion which occurs at Pomt Ldvis. (Trans. 

 Acad. Sci., St. Louis, vol. ii, May, 1862). 



1863. — Peof. J. Hall revised a number of the above named species 

 from the Potsdam sandstone of Wisconsin, and described the followino- new 

 ones : Lingula Winona, L. Moisa, L. Aurora, Biscina inutilis, Oholellal 

 poUta, Orthis Pepina, Platyceras primordialis, Uuomphalus vaticinus 

 Theca primordialis, Serpulites Marchisoni, Bikelocephalus limbatus, D. 

 spiniger, D. Misa, D. Osceola, Conocephalites JEos, C. Perseus ; C. Shu- 

 mardi, 0. nasutus, C. Otveni, C. Eryon, C. anatinus, 0. Pattersoni 

 C. hijwdosus, C. Winona, 0. diadematus, C. optatus, C. nactus, C'ha- 

 7'iocephalus Wldtfieldi, Tllcenurus quadrahis, Triarthrella Auroralis, 

 Agnostus Joseplia, A. parilis, A. dlsparilis, Aglaspis Barrandei, 

 Pemphigaspis bullata, and Amphion matutina. The new genera of 

 trilobites described in this paper are PejnpMgasjns Aglaspiis, Triarthrella, 

 Illcenurus, Charioceplialus and Ptychaspis. In the last of these is j)laced 

 Owen's two species, Bikelocephalus Minnesotensis and B. granulosus. All 

 the species are illustrated by excellent figures. (16th Reg. Rep.) 



1864. — Proi?. a. "Winchell, of Michigan, described Orthis Ba/rahuen- 

 sis, Straparollus ( Ophileta^ primordialis, PleurotomariaAdvena,Ptychas- 

 pis Barabuensis, Palceophycus articulatus, and P, informis, from the 

 Potsdam sandstone of Sauk County, Wisconsin. He also reports from the 

 same locality, Scolithis linearis, B. Minnesotensis and B. Pepinensis. 



In addition to the above, Prof. Hall has described from the Potsdam 

 group in Vermont Olenellus Vermontana, 0. Thompsoni and Bathynotus 

 Molopyga. There will also be found in this work the following twenty-two 

 species, — Soolithus Canadensis, Palceop>hycus incipiens, P. congregatus, 

 Archeocyathus Atlanticus, A profundus, Obolus Labradoricus, Obolella 

 chromatica, 0. (^Kutorgina') eingulata, Orthisina festinata, Camerella 

 antiquata, Conocephalites miser, C. Adamsi, C. Vuleanus, C. Teucer, 

 C. arenosus, Bathyurus senectus, B. parvulus, B. vetidus, B. perplexus, 

 iSalterella rugosa, S. pidchella, and S. obtusa. 



There are also in Canada certain beds, at present considered to form 

 the upper layers of the Potsdam, which hold Lingula acuminata, Ophileta 

 compacta, Pleurotomaria Canadensis, and a small orthoceratite. It may 

 be that these beds should be placed in the base of the Calciferous, and, 

 therefore, in the following comparisons the fossils they hold will not be 

 taken into account. 



