Geology and Mineralogy. 499 



* 



Horton Bluff, Nova Scotia, and remarks that the genus is prob- 

 ably confined to this period. 



Other fossil species are described in the same volume from the 

 Erie shale of Ohio — the western extension of the Chemung and 

 Portage rocks of New York and Pennsylvania. They include 

 Cladodus Kepleri Newb., Actinophorus Clarkii Newb., Diuich- 

 thys curtus Newb., D. tubercidatus Newb. D. curtus has been 

 found in the Chemung of Pennsylvania. 



The Annals of the New York Academy of Sciences for Febru- 

 ary, 1888 (vol. iv), contains a description and figures by Dr. New- 

 berry of a new and gigantic species of Edestus, E. giganteus, 

 from the coal measures of Decatur, Illinois, with a history of the 

 genus and notes on the species. The specimen is shown to be the 

 dorsal spine, of a gigantic Plagiostome. The spine, which was 

 18 inches or more in length, had the great breadth of 7-| inches 

 including the denticles, and was two inches thick at center ; the 

 broad triangular denticles were 3-£ inches long with the edges 

 coarsely denticulate. The species was much larger than E. vorax 

 of Leidy or E. Heinrichsii of Newberry and Worthen, and differ- 

 ent also in the form of the teeth. An admirable figure of the 

 specimen accompanies the paper, with also figures of the other 

 American species. 



3. Natural History of New York. Palceontology, vol. vii, 

 with Supplement to vol. v, part II ; by James Hall, State Geolo- 

 gist and Palaeontologist, assisted by John M. Clarke, pp. lxiv, 236, 

 4 to 45 plates, and pp. 42, with 18 plates. Albany, 1888. — This 

 new volume of the Palaeontology of New York is devoted 

 principally to the Devonian Crustacea of North America, exclu- 

 sive of the subclass Ostracoda. The introduction presents a brief 

 historical sketch of the class as limited to American forms; also, a 

 table showing a systematic arrangement of the subclasses, orders, 

 families and genera, followed by a discussion and tabulation of 

 their chronological distribution. It is shown that the richest trilo- 

 bitic fauna is in the Corniferous limestone, which has afforded 

 52 species of Crustacea, of which 49 are trilobites and 3 are 

 cirripeds. The generic synonymy and a diagnosis of each genus, 

 with outline figures in the text, precede the main descriptive 

 matter of the volume, and will furnish much assistance to the 

 student of this class of fossils, as well as many valuable refer- 

 ences and suggestions to the systematic palaeontologist. 



The descriptions of species are given in a logical and complete 

 manner. There are 127 species and varieties of Devonian Crus- 

 tacea described, which are arranged in 28 genera. The trilobites 

 include 10 genera and 83 species ; the Xiphosura 1 ; the Euryp- 

 teiida 2 genera and 3 species ; the Phyllocarida 8 genera and 26 

 species; the Decapoda 1 genus and a single species; the Phyllo- 

 pocla 2 genera and 2 species ; and the Cirripedia 4 genera and 11 

 species. 



One of the most interesting of the genera of Trilobites considered 

 in the volume is that of Dalmanites. It comprises 25 species and 



