SCORPIONES. 9 



The Phalangiotarbi are retained as a valid group containing the following- 

 families and genera with their type species : 



Family Phalangiotarbid^e. 



Genus Phalangiotarbu', Haase: P. subovalis, Woodward. 

 Family Architarbid^i. 



Genus Architarbus, Scudder: A. rotundatus, Scudder. 



Genus Geraphrynus, Scudder : G. carbonarius, Scudder. 



Genus Geratarbus, Scudder : G. lacoei, Scudder. 



Genus Opiliotarbus, nov. : 0. elongatus, Scudder. 



III.-SYSTEMATIC ACCOUNT OF THE BRITISH SPECIES. 



Order SCORPIONES, Latreille. 



The Carboniferous Scorpions were formerly assigned by Thorell and Lindstrom 

 to a special group, Anthracoscorpii, on the supposition that the median eyes were in 

 advance of the lateral eyes, instead of behind them as in recent Scorpions or 

 Neoscorpii. This supposition has no foundation in fact, so far as is known. 

 Perhaps, indeed, the most useful contribution that Fritsch has made to our 

 knowledge of fossil Scorpions, is his discovery that the so-called posterior row of 

 eyes described by Corda in Cyclophthalmus senior are in reality tubercles. Fritsch, 

 however, still preserved the name Anthracoscorpii for the Carboniferous species 

 collectively, although justification for this course was not supported by any new 

 definition of the group. 



Nevertheless, some of the Carboniferous Scorpions differ from all recent forms 

 in one or two characters of great morphological interest. In the specimen des- 

 cribed below from the Coal Measures of Sparth, belonging to the collection of 

 Mr. F. Holt, the sterna of the fourth, fifth, and sixth segments of the opisthosoma 

 end posteriorly in a pair of widely rounded laminate lobes, which are separated by 

 a median angular notch and manifestly overlap the anterior portion of the sterna 

 that succeed them. I am unable to say whether the sternum of the third was 

 similarly constructed ; possibW not, since it was evidently covered to a great extent 

 by the pectines of the second sternal plate, which was of large size — much larger, 

 indeed, than in any recent species. Moreover, the basal segments of the legs of 

 the fourth pair do not apparently abut against the sternal plate of the prosoma, 

 as in existing Scorpions, but against the sides of the genital operculum, a feature 

 quite unknown in existing species, in which the coxa3 of the third and fourth legs 

 are united to form a wedge-shaped skeletal piece diverging obliquely backwards 

 and outwards from the sternum of the prosoma. The figures published by Fritsch 



of the types of Eobuthvs rctlcovnicensis and of hobuthus kralupensis seem to agree 



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