12 TERRESTRIAL CARBONIFEROUS ARACHNIDA. 



in several Scottish species, referable to more than one genus, as " embossed scale- 

 like pattern." It is not known whether Gyclophthalmus possessed this character 

 or not. 



A glance at Peach's figures of Scottish Carboniferous Scorpions shows that at 

 least two genera must be admitted. One of the species, described as Eoscorpius 

 euglyptus, has the large cheliceraa and stout chela? of Gyclophthalmus, and I am 

 unable to say that it does not belong to that genus. Eoscorjrius glaber, on the 

 contrary, is a totally different form ; and it also differs in the shortness of its legs 

 and the structure of its chela? from all the other European genera where these 

 organs are known. For this I propose a new generic name, Archseoctonus. A 

 third British genus seems to be represented by the species described as Eoscorpius 

 anglicus by Dr. Henry Woodward. The remaining British species are, for reasons 

 discussed below, assigned to the genera Anthracoscorpio, Kusta, and Eobuthus, 

 Fritsch. 



The subjoined table shows the main features by which these genera may be 

 tentatively distinguished from each other : 



a. Hand of chelae wide and oval, greatly exceeding the brachium in width ; fingers very 

 short, the movable about equal to the width of the hand. [Caudal segments 

 apparently very short and broad and not sensibly increasing in length posteriorly ; 

 legs and sterna unknown.] ...... Pahvomachus. 



«'. Hand of chelae wide or narrow, but at most only exceeding by a little the width of 

 the brachium ; fingers, except perhaps in Eobuthus, long, the movable much longer 

 than the width of the hand. 



b. Legs exceedingly short, the fourth, when extended, not reaching the end of 

 the abdominal portion of the opisthosoma ; its femur much shorter than 

 the carapace. [Sterna of abdomen with straight posterior borders ; coxse 

 of third and fourth legs apparently abutting against the sternum of the 

 prosoma.] ....... Archeeoctonus. 



V. Legs of normal length, the fourth, when extended, surpassing the posterior 

 end of the abdomen ; its femur about as long as the carapace, 

 c. Coxse of third and fourth legs abutting against the sternum of the 

 prosoma ; the posterior border of the sterna of the fourth, fifth, 

 and sixth segments of the opisthosoma straight or nearly so. 

 d. Chelae heavy and massive, with stout, strong fingers. 



Cyclophthalmus. 

 d'. Chelae comparatively light and slender, with thin fingers. 



Anthracoscorpio. 



c . Coxse of legs of third pair abutting against the sternum of the 



prosoma, those of the fourth against the genital operculum ; sterna 



of fourth, fifth, and sixth segments of opisthosoma markedly 



bilobate and laminate posteriorly. . . . Eobuthus. 



