514 A. W. GRABAU PALEOZOIC DELTA DEPOSITS OF XORTH AMERICA 



vonic beds of Campbellton, Xew Brunswick. Other fragments have been 

 reported from the Knovdart formation of Arisaic, Xova Scotia, where 

 they are associated with remains of Pteraspis and Cephalaspis. This 

 horizon may be of Upper Silurie age. The Portage sandstone of Yates 

 County. Xew York, has furnished a specimen of Stylonurus ( ?) wright- 

 ianus (Dawson). A number of fragments of Stylonurus. originally 

 described as Stylonurus excelsior by Hall and which Beecher used in mak- 

 ing the restoration, which he called Stylonurus lacoonus. have all been 

 united by Clarke and Euedemann under the species Stylonurus (Ctenop- 

 terus) excelsior. There are only two specimens, one a complete carapace 

 from the Catskill beds at Andes, Delaware County. Xew York, and an- 

 other more fragmentary carapace from the same formation in Pennsyl- 

 vania. Eurypterus beecheri Hall, described from the Chemung of Penn- 

 sylvania, has proved to be the same as Stylonurus beecheri. George F. 

 Matthew has described some very doubtful fragments as Eurypterella 

 ornata from the plant bed number 2 of the Little River group in the 

 Devonic (probably Carbonic) of Xew Brunswick, but Clarke and Euede- 

 mann have been unable to identify the material. Aside from the species 

 of the Little Biver group, there are only four identifiable species known 

 from the Devonic of Xorth America. 



Post-Devonic. — The only Eurypterids from the Mississippic are four 

 species of Eurypterus from Great Britain and one from the Waverly of 

 Pennsylvania. E. scouleri Hibbert was described from Kirkton, West 

 Lothian, where it occurs associated with fishes, stems, leaves, fruits of 

 Lepidodendron, calamites. and other plants. The beds, too, are rich in 

 Entomostraca, and particularly in the fern Sphenopteris affinis. Wood- 

 ward, speaking of this formation, says that it is "a fresh-water deposit, 

 and abounds in bands of silex, alternating with calcareous matter, and 

 presents all the appearance of having been deposited by thermal waters 

 during the Carboniferous epoch."' Erom Eskdale. Scotland, one well 

 preserved, but doubtfully identified species. Eurypterus scabrosus Wood- 

 man, has been reported. Peach describes two species. Glyptoscorpius 

 perornatus and G. caledonicus Salter (originally described by that author 

 as Cycadites caledonicus, a plant fragment), from the Calciferous sand- 

 stone series near Cockburnspath. on the Scottish border, a formation 

 equivalent to the Xorth American Mississippic. The American species. 

 Eurypterus approximatus Hall and Clarke, conies from Devono-Missis- 

 sippic transition beds, if not actually from the Chemung. 



With the Carbonic we approach the extinction of the Eurypterids. 

 Five species from Xorth America and seven from Great Britain and 



