THE SCOTTISH SILURIAN SCORPION. 293 



'^ hand " of tlie chela, and not across its posterior portion as 

 shown in the figure in 'Nature/ One or two other particu- 

 lars in which I differ from him are referred to in the followino- 

 pages. 



The specimen gives the following measurements in milli- 

 metres : — Total length on stone 32*5, actual total length when 

 extended 35"5, trunk 16'5, tail 19. 



The Gotland specimen is considerably larger, measuring 

 62 mm. in total length, the tail being at least 26 mm. 



Prosoma. — Owing to the outward displacement of the 

 chelae the anterior portion of the carapace is visible between 

 the basal segments of these appendages, and in front of those 

 of the first pair of legs. Its surface is thickl}^ granular, its 

 anterior border lightly concave, as is the Gotland specimen, 

 and its antero-lateral angles subquadrate. 



Eyes. — In the Gotland specimen no trace of eyes, either 

 median or lateral, is discernible, though the median ocular 

 tubercle of recent scorpions is represented by a relatively 

 large and longitudinally oval elevation, situated in the ante- 

 rior third of the carapace, and separated from its anterior 

 edge by a space equalling about one half the length of the 

 elevation. Judging from the figure, this tubercle is pre- 

 served in its entirety; hence there is no reason to doubt 

 that if eyes had been borne upon it, some trace of them at 

 least would have been preserved. 



In the Scotch specimen also there is no sign of the lateral 

 eyes. If, however, as is possible, these organs existed, and 

 were placed behind the level of the median eyes, as is the 

 case in the normal Pedipalpi, and, as is alleged, in the Car- 

 boniferous Anthracoscorpii, they would be concealed from 

 view beneath the basal segments of the anterior legs, which 

 on each side overlie that portion of the carapace immediately 

 behind the median eyes. The median eyes are very distinctly 

 represented by a pair of elliptical impressions situated close 

 together, one on each side of the middle line, and scarcely 

 more than their own long diameter from the anterior border 

 of the carapace. There is no evidence that these eyes were 



