THE SCOTTISH SIL0EIAN SCORPION. 309 



Scudder. The latter (Zittel's ' Handbuch der Palaontologie/ 

 ii, p. 739, 1885) classified it with the Carboniferous scorpions 

 on account of the alleged presence of a pair of claws at the 

 extremity of the anterior leg of the left side. This classifi- 

 cation was endorsed by Whitfield, who based the genus 

 Proscorpius mainly upon these claws, declaring them to 

 be very similar to those of living forms. His figure shows 

 no such similarity. The apical segment of the leg is simply 

 bifid at the tip, a feature which may be due to fracture, or 

 may represent a pair of sclerites like those borne at the tip 

 of the distal segment of the fourth leg of Limulus; or may 

 be explained on the supposition that the end segment ter- 

 minated in a sharp point as in Palgeophonus, and was 

 furnished near the tip with a moveable spine or spur. Since, 

 however, there is no agreement between Scudder and Whit- 

 field as to whether the segment stated to possess these claws 

 is numerically the third or sixth from the base, it seems idle 

 to discuss the matter further. If Scudder^s interpretation 

 of the numbers of the segments is correct, these " claws ' 

 are situated at the end of the third or fourth segment, and 

 cannot be compared with the tarsal claws of other scorpions. 



Apart from the leg, the chief points of interest connected 

 with Proscorpius shorn i are the presence of a pair of 

 eyes on a median ocular tubercle, and of a row of lateral eyes 

 (not shown in the figures, by the way) on each side of the 

 carapace. The rounded median tubercle projects in the 

 middle line of the fore border of the carapace, the lateral 

 angles of which are also I'ounded. Hence the trilobate 

 appearance of the anteiior border of this plate, which forms 

 such a contrast to the even emargination seen in the Swedish 

 and Scotch Palteophonus. It is further to be noticed that 

 the dorsal integument is smooth, and not granular as in 

 Palseophouus nuncius. 



Along the right-hand side of the specimen, both Scudder 

 and Whitfield agree that six (five mesosomatic and one 

 metasomatic) abdominal sternites are exposed. The first of 

 these belongs to the second mesosomatic somite, which in 



