126 Proceedingi^ of Indinua Academij of Science 



the origin of the vertebrates which is discussed at lengtli by Patten'' 

 and Gaskeir. 



Pref!e)it Sfute of llw Knvirlcdgc o)i FoshU Scorpio}!^. Petrunke- 

 vitch' also thinks the Water-Lime specimen must have been a marine 

 form, and here it might be well to add a few words on the conclusions 

 reached in his study of the phylogenetic development of the scorpions. 

 He says: "That the different classes of arthropods must have developed 

 not from one ancestor but at different times and from different species 

 of chaetopodous worms;" that the scorpions no farther back than Car- 

 boniferous times were not equipped with internal lung books and in 

 the structure of these parts they do not resemble the eurypterids as was 

 suggested by Pocock; that eurypterids have in some respects closer 

 relations with limuloids than with scorpions; that the Bertie water-lime, 

 which contains the eurypterid having the closest resemblance to scor- 

 pions, also contains the oldest true American scorpion; and finally, that 

 the Xiphosura, Eurypterida and scorpions developed independently and 

 that the great similarity is due to convergence as Thorell suggested. 

 Some have suggested that the different sub-classes "must have been 

 differentiated even in Pre-Cambric times''." The well preserved speci- 

 mens from the Oligocene indicate that the scorpions then had prac- 

 tically the same habits as they possess today. Schuchert'", in his dis- 

 cussion of the Silurian forms, after summing up the evidence, concludes 

 that they were semi-aquatic, living along- the shore, above the Strandline, 

 feeding on small crustaceans and other small invertebrates. 



Fossil Carboniferous Scorpions. The Carboniferous scorpions have 

 been extensively treated, by Fritsch in continental Eurcpe, Pocock in 

 England and Petrunkevitch in North America. Petrunkevitch in de- 

 scribing the 16 available specimens from North America placed them 

 in ten species, six genera and four families. The likeness between some 

 of the Carboniferous forms and the recent forms is very striking. 



Present State of Classification of the Order. Each one of the work- 

 ers in this field has arrived at a different conclusion as to the classifi- 

 cation of the order; so I will here give a brief summary of the existing 

 state of the classification. 



The Classification of Karscli. Karsch" divided the order into four 

 genera, Eoscorpius, Microlabis, CycUiphthahnvs and Mazonia. In his 

 classification Eoscorpiits Meek anri Worthcn contained: Anglicns, 

 Woodward and Carbonarius, Meek and Woi'then. Microlabis Corda, 

 contained the species sternbergii Corda. Cyclophthalmus Corda, 

 contained the species senior Corda. Mazonia Meek and Worthen, con- 

 tained the species woodiana Meek and Worthen. 



Work of Scndder and His Classification. Scudder" in his work two 

 years later recognized only three genera placing all of them in the 



" Patten — The Evolution of the Veitebiates and Their Kin. 



' Gaskell — The Origin of the Vertehrates. 



^Petrunkevitch — Trans, of Conn. Acad, of Arts and Sciences, Vol. 18. 



■' Peti'unkevitch — Tran.s. of Conn. Acad, of Arts and Sciences, Vol. 18. 



'" Schuchert Textbook of Geolouy. Vol. II. 



"Karsch, F. E. Zeitschr. deulsch. Geol. Cos. (1882). pi). .-,r>(;-r,«l . 



1= Scuddcr, S. H. Pioc. Anier. Acad. Arts and Sciences, Vol. XX. 1881. VV- l')-22. 



