PALEOZOIC TIME UPPER SILUKIAN. 



551 



Wh., from the Niagara beds of Ohio, Fig. 770. The Star-fishes, Palceaster Niagarensis 

 H., Glyptaster occidentalis H. 



5. MoUuscoids. — (a) Bryozoans. — Many species of delicate Corals of the genus 

 Fenestella, resembling Fig. 751 ; Trematopora, and other genera. (6) Brachiopods. — 

 Fig. 771, Leptoeno, rhomboidalis Wilck. ; 772, Plectamhonites transversalis Dalman ; Stro- 

 phomena depressa Sow. ; 773, Atrypa nodostriata H., the Niagara form of this species ; 

 773 a, same, side view ; A. reticularis Linn. ; A. rugosa H. ; 774, Meristina ( Whitfield- 

 ella) nitida H. ; 775, Anastrophia interplicata H. ; 776, a, Bhynchotreta cuneata Dalm. ; 

 777, a, b, Atrypina disparilis H. ; 778, Orthis (Bilobites) biloba Linn., 778 a, same, 

 enlarged ; 0. elegantula Dalm., 0. hybrida Sow., Nucleospira pisiformis H. ; 779, Spirifer 

 Niagarensis Con., 779 a, same, side view ; 780, «, Sp. stilcatus His. ; Pentamerus oblongus 

 (Fig. 752), a Clinton group species, abundant in the Niagara limestone of the Mississippi 

 basin ; Pentamerus occidentalis H., from the Guelph. 



6. Mollusks. — (a) Lamellibranchs. — Fig. 781, Megalomus Canadensis H., from the 

 Guelph, Canada ; 782, Avicula emacerata Con. ; Orthonota curta H. 



(6) Gastropods. — Fig. 783, Platystoma Niagarense H. ; 784, Platyceras angulatum 

 H. ; Murchisonia bivittata H., M. macrospira H., Subulites ventricosus H., Pleurotomaria 

 solarioides H. 



(c) Pteropods. — Coniilaria Niagarensis H., C. longa H., Lockport. 



(d) Cephalopods. — Orthoceras anmilatum Sow., 0. rectum Worthen, Orthoceras 

 (Kionoceras Kjutt) sJnx Worthen ; Phragmoceras parvum H. and Whitf., Huronia Bigs- 

 hyi Stokes, H. vertebralis Stokes, Gomphoceras Wabashense and G. angustum Newell, 

 Pentameroceras mirum Barrande, Ascoceras Newberryi B. , Hexameroceras delphicolum 

 Newell, etc., Lituites Marshi Hall, Trochoceras costatum H., T. notum H.,T. Desplain- 

 ense McChesney. 



7. Crustaceans. — Fig. 785, Dalmanites limidurus Green ; 786, Lichas Boltoni Bigsby ; 

 787, Homalonotus delphinocephalus Green, one specimen 7 inches long and 5 broad ; 788, 

 Illcenus loxus H. ; Calymene Niagarensis H. , near Fig. 690 ; Ceraurus Niagarensis H. ; 

 Proetus Stokesi Murch., at Lockport. 



The following genera and species of fossils have been identified in the Niagara beds 

 ■of Littleton, N.H. : Favosites basalticus, F. Gothlandicus, Syringopora, Stromatopora, 

 Halysites near catenulatus, Zaphrentis, Leptcena rhomboidalis, Stropheodonta, Pentamerus 

 Knightii, Trematospira muUistriata H., Pleurotomaria, Dalmanites limidurus abundant. 



In the Anticosti beds there are Cephalopods of the genera Orthoceras, Cyrtoceras, 

 Oncoceras, Ascoceras, and Glossoceras ; and Trilobites of the genera Asaphns, Calymene, 

 Illcenus, Phacops, Dalmanites, Encrinurus, Harpes, Lichas, etc., and among these Asaphus 

 megistos and Calymene Blumenbachii. 



A section of the Anticosti group, or that of Anticosti Island, on the north side of the 

 St. Lawrence Bay, opposite Gasp§, is particularly described by Logan in the volume of 

 the Canadian Survey for 1863 (pages 298-310), and the fossils in its successive parts are 

 enumerated from determinations by Billings, and also, where new, described by the latter. 



The following are some of the species common to the Niagara and Clinton groups : — 



Halysites catenulatus (Fig. 763). 

 Caryocrinus ornatus (Fig. 768). 

 Eucalyptocrinus decorus. 

 Lingula lamellata. 

 Orthis elegantula (Fig. 723). 

 LeptEena rhomboidalis (Fig. 771). 

 Pentamerus oblongus (Fig. 752). 

 Ehynchonella neglecta. 

 Atrypa reticularis (Fig. 754). 

 Spirifer radiatus. 



Avicula emacerata (Fig. 782). 



Orthonota curta. 



Modiolopsis subalata. 



Ceraurus Niagarensis. 



Homalonotus delphinocephalus (Fig. 787). 



Calymene tuberculosa. 



Calymene Niagarensis. 



Dalmanites limulurus (Fig. 785). 



Illsenus loxus (Fig. 788). 



