PALEOZOIC TIME — LOWER SILURIAN. 515 



Troclwceras of Barrande by Foord, and named T. Halli Emm. ; Fig. 688, Trocholites 

 Ammonuis Hall, from the Trenton, at Middleville, N.Y. Whiteaves has described and 

 figured several species of the Orthoceras family from Manitoba, from the vicinity of 

 Winnipeg Lake and elsewhere (1891). 



7. Worms. — Serpiilites dissolutus B., Trenton, Canada; Salterella Billingsi Saff., 

 Tennessee. 



8. Crustaceans. — Fig. 689, Asaphus platycephalus DeKay ; Fig. 690, Calymene calli- 

 cephala Green ; Dalmanites (Phacops) callicephalus H. ; Fig. 691, Lidias Trentonensis 

 Con.; L. cucullus M. & W., Illinois; Fig. 692, Trimicleus concentricus Eaton; Ceraurus 

 pleurexantliemus Green ; lUcenus crassicauda Wahl. , New York and Illinois ; /. Taurus H. 

 Other genera are Bathyurus, Triarthrus, Acidaspis, Encrinurus, Harpes, Proetus. 



Fig. 693, Leperditia fabulites Con., New York, Canada, and Tennessee; L. armata 

 Wale. ; L. Canadensis Jones ; Beyrichia bella Wale, Trenton Falls. 



9. Vertebrates. — For Walcott's account of the discovery of the remains of Fishes in 

 the Trenton of Colorado see Bull. Geol. 8oc., iii., 153, March 15, 1892. It was announced 

 to the Biological Society of Washington, at a meeting, February 7, 1891. The remains 

 were first found in the Harding sandstone, near Harding quarry, within a mile of Canon 

 City. They also occur in Helena Canon, 18 miles to the north-northeast. The section at 

 the latter place, above the Archtean gneiss, consists of 22J' of arenaceous limestone with 

 thin layers of chert, containing Upper Cambrian fossils ; 51' of a similar rock, with Cal- 

 ciferous species, of the genera Ophileta, Straparollus, etc. ; 101' of sandstone — the Hard- 

 ing sandstone — containing the plates of Placoderms and Lower Trenton fossils; 110' of 

 massive arenaceous limestone ; a thin band of Carboniferous limestone. The section is 

 repeated many times in the canons, removing all doubt, says Walcott, as to the strati- 

 graphic position of the Harding sandstone. There are no strata of the Upper Silurian or 

 Devonian series at either of the localities. 



The characteristic species of the Galena limestone include Beceptaculites Oweni Ji., 

 Halysites cateiiulatus, Lingulela lowensis Owen, Clitamhonites Americanus Whitf., Mur- 

 chisonia major H., Fusispira ventricosa H., F. elongata H., Maclurea cuneata Whitf., 31. 

 suhrotunda Whitf. 



2. Utica and Hudson Epochs. 



Figures representing the supposed terrestrial plants described by Lesquereux from 

 the rocks of the Cincinnati group near Cincinnati, 0., and Covington, Ky., are contained 

 on page 198 of the last edition of this vpork. Dr. Newberry, after an examination of the 

 specimens, published the same year his opinion against them. 



1. Spongiozoans. — Cyathophycus reticiilatus Wale, and C. suhsphericus Wale, from 

 the Utica slate, Oneida County, N.Y. Trans. Albany Inst., x., 18, 1879. Species of 

 Pasceolus, Astylospongia, 3Iicrospongia, Beceptaculites, Brachiospongia. 



2. Actinozoans. — In the Hudson beds, Favistella stellata H,, Fig. 704 ; several species 

 of Columnaria ; Cyathophylloids of the genus Petraia, as in the Trenton ; also of the genus 

 Zaphrentis, Z. Canaxlensis B. ; Halysites gracilis H., Fig. 705, from Green Bay, Wis. ; 

 Sarcinula? obsoleta H., Fig. 706 ; Tetradium fibratum, Saff., from Tennessee, etc.. Figs. 

 707, 707 a ; T. cellulosuni, the Birdseye species from Kentucky. 



3. Hydrozoans. — The species of Graptolites figured on page 510 are a few from the 

 large numbers afforded by the Utica and Hudson shales. The specimens for figures 699, 

 CfEnograptus gracilis, and 702, Dicranograptus ramosus, besides others, were from the 

 Normanskill shales near Albany. The age of these shales has been questioned by Lap- 

 worth on paleontological grounds (Trans. Boy. Sac. Canada, iv., pages 167-172). The 

 New York State geologists have considered the beds to be equivalent to the Hudson River, 

 or the Utica shales, or to both. Lapworth refers the Graptolites to his " Ccenograptus zone " 

 of Llandeilo age, equivalent to the Black River and Trenton limestones. The same beds 



