Page:The Eurypterida of New York Volume 1.pdf/148

 features of their order. Recently a fossil Thelyphonus from the Bohemian Carbonic,  (Kusta), has been fully made known by Fritsch [1904]. Unfortunately the specimen shows the ventral aspect only, more or less involved with the dorsal side. But if we read the figures 5, 6 and 7 of his plate 6 aright, the ventral segments in Carbonic time still possessed a like development with the dorsal ones and the agreement of the Pedipalpi with the eurypterids in the greater development of the genital plate would have manifested itself only after the disappearance of the eurypterids and so lack phylogenetic significance.

Some very significant points regarding the relationship of the eurypterids and scorpions have been brought out by Pocock's investigations [ 1901] of the Scottish Siluric scorpion,. We briefly note the more important of these. Pocock points out that the walking legs of Palaeophonus differ from those of all other scorpions, living or fossil, in their primitive character [text fig. 28]. They consist of the primitive number of segments (seven), show the simplicity of segmentation by the subequality of the individual segments and possess a sharply pointed, practically clawless terminal segment, strikingly resembling those of some eurypterids (Pterygotus) and differing greatly from those of the recent scorpions. Further, in distinction from the later scorpions, the basal or coxal segments of all the appendages were in contact or capable of meeting in the middle line, although the coxae of the fourth were small and functionless [ text fig. 85]. In this feature the archaic Palaeophonus