26 A/exandrr Pftrmikevitcli, 



presented in the Xorth American Carboniferous fauna bj- the genus 

 Generalinura with 3 species. In England it is represented by i species, 

 G. hritannica, and in Bohemia by G. bohemica. The real generic 

 characters used in the systematics of recent whip scorpions are not 

 preserved in the Carboniferous specimens, and the American species 

 may in reality belong to a different genus from the European ones. 

 The sub-order Amblypygi is represented in this country by 3 species 

 belonging to as many genera, one of which, namely Graeophonus, 

 has also a representative from England in G. anglicus. The order 

 Scorpiones is at present restricted to tropical and hot countries with 

 2 species, however, living as far north as the Karpathian mountains 

 and southern Germany, and several other species in southern Europe. 

 In the United States occur 22 species of scorpions, two of which go 

 as far north as Colorado, Utah, Nevada and Nebraska. Leaving out 

 of consideration Mazonia woodiana from Mazon Creek, a species 

 which may eventually prove to be not a true scorpion, the Carboni- 

 ferous scorpions may be divided into 3 families, at least one of which, 

 Isobuthidae, is distinct from all recent scorpions and therefore ex- 

 tinct. This family is represented in Europe by 3 species belonging 

 to 2 genera, and by a third with a single species in North x\merica. 

 The family Cyclophthalmidae is represented in Europe b\' 3 genera 

 with 5 species. A fourth, rather uncertain genus is represented by 

 a single species in North America. The family Eoscorpionidae shows 

 many relations to recent Scorpionidae and Vejovidae and represents 

 probably two or three families thrown together for lack of distinctive 

 characters. The genus Microlahis with its single species, M. sternbergi 

 is known only from Europe. The genera Palaeopisthacanthiis with 

 2 species and Trigonoscorpio with a single species are American. Of 

 the genus Eoscorphis 4 species occur in Europe and 4 in this country. 

 While any conjecture as to the direction in which the phylogenetic 

 development of arachnids took place in Europe and North America, 

 would be premature, the following conclusions seem to have suffi- 

 cient foundation in fact : (i) that the Carboniferous arachnological 

 fauna of North America is distinct from that of Europe and developed 

 along somewhat different lines, and (2) that both faunas have more 

 similaiity with recent faunas of tropical countries, than with such of 

 the same locality. 



