PALEOZOIC TIME — DEVONIAN. 601 



Dawson thereupon observes that " the trill and hum of insect life must have 

 enlivened the solitudes of the strange old Devonian forests." Insects appear 

 to have been the only winged life of the Devonian and Carboniferous ages. 



8. Vertebrates. — Remains of Fishes occur sparingly in the Hamilton beds, 

 while abundant in the overlying Genesee and Portage beds. Those observed 

 are the plates or fragments of jaws of Placoderms, or teeth or fin-spines of 

 Selachians. One of the large fin-spines, from the Hamilton beds of Yates 

 County, IST.Y., called Ctenacanthus Wrighti by Newberry, is nine inches long 

 and an inch and a half in diameter at base. 



Characteristic Species. 



Plants. — The seaweed, Spirophyton, occurs in the Hamilton and through the later 

 Devonian. Fig. 894, of Lepidodendron priincevtcm, Rogers, shows only the inner surface of 

 the bark, and not the true surface scars. Fig. 896 is one of a group of leaves of Cordaites 

 Eobbii, figured by Dawson ; and Figs. 897, 898, from Dawson, are portions only of his 

 figures. For J. M. Clarke's papers on Sporangites, see Am. Jour. 8c. , xxix., 1885. 



Animals. 1. Spongiozoans. — Sphcerospongia tesselata (Fig. 902) is associated with 

 Terehratula (Eunella) Sxdlivanti Hall, of the Corniferous, Spirifer fimhriatus Con., Pen- 

 ta.nerus comis, Atrypa reticidaris, Nucida lirata Hall, of the Hamilton shales, Para- 

 cyclas elliptica Hall, of the Corniferous and Hamilton, Goniophora perangulata Hall, of 

 the Schoharie grit, etc. ; also, the following European species, not known from the United 

 States, Murchisonia turhinata, Euomphalus annularis, Stringocephalus Burtini, Loxonema 

 priscutn, Macrochilina subcostata, etc. The Stringocephalus is characteristic of the 

 "Stringocephalus zone" of the Middle Devonian of Europe. The Devonian fossils of 

 Manitoba, according to Whiteaves, have close relation to those of Europe, while many 

 differ in species from those of the United States. 



2. Actinozoans. — Fig. 903, Heliophyllum HalU E. & H., N.Y., H. obconicum H., 

 H. conjluens H., Cyathophyllum robustum H., C. nanum H., C. conatum H. ; Zaphrentis 

 Halli E. & H., Z. simplex H., Cystiphylhim varians H., C. Americanum E. & H., C. 

 conifollis H., Amplexus Hamiltoniae, H. ; Michelinia stylopora Eaton, Favosites placenta 

 Rominger, F. arbuscula H., F. Hamiltonioe, F. Argus, all from a "coral-reef" area of 

 the N.Y. Lower Hamilton, near Canandaigua, N.Y. (Clarke), and nearly equally abundant 

 to the westward in New York and Ontario. 



3. Echinoderms. — The forms, described under the generic name, Heteroschisma, by 

 Wachsmuth, from Iowa, show a relation between Cadaster and Pentremites (III. G. Hep., 

 vii., 1883). 



4. Molluscoids. — Large numbers of Bryozoans are described in Hall's vol. vi., of the 

 N. Y. Geological Survey. 



Brachiopods. — Fig. 904, Atrypa aspera Schloth, also European; 905, A. reticularis, 

 larger than the same in the Corniferous, and fuller, sometimes nearly 2 inches broad ; 

 906, Tropidoleptus carinatus H., New York, Illinois, Iowa, Europe ; 907, Spirifer mucro- 

 natus Con., very common ; 908, Athyris spiriferoides Eaton ; 909, AmboccElia umbonata, 

 N.Y. and the West ; 910, Chonetes setigerus H., in the Marcellus and Genesee shales, and 

 also the Chemung; 911, Productella subalata H., Rock Island, 111. ; Spirifer granuliferus 

 H., a large species, having a granulated surface. 



The Bhynchonella cuboides is chai'acteristic of the Tully limestone ; and as beds 

 containing this species and others associated with it in England and Europe are referred 

 to the base of the Upper Devonian, the "Frasnian stage," the limestone, according to 

 H. S. Williams, ought to be arranged with the Upper Devonian in New York, etc. He 



