ICJ Froceedings of Indiana Academy of Science 



are four more pairs of appendages, the six-jointed walking legs. The 

 abdomen is also supplied with modified appendages. The first segment 

 of the praeabdomen probably bsars the genital opening. The second 

 abdominal segment bears a pair of appendages called the pectines, or 

 so-called combs whose function is not very well understood. The ven- 

 tral surfaces of the third to sixth abdominal segments, inclusive, bears 

 each a pair of stigmata, the exterior openings to the lung-books which 

 are the respiratory apparatus. 



The eyes are situated on the dorsal surface of the cephalothorax 

 and vary from two to six in number. One pair of eyes are larger and 

 are situated near the median line. The others which are smaller are 

 lateral. Some of the modern forms are blind. 



Scorpions are viviparous, the genital orifice occupying the same 

 position in both sexes."' 



The I)idiana Specimen. The specimen here under discussion was 

 .secured by Arch R. Addington in Clay County, Indiana, while serving in 

 the capacity of assistant to the State Geologist. Mr. Addington recog- 

 nized the importance of the fossil and later presented it to P. D. Moore, 

 who in turn placed it in my hands for study and description. 



Condition of the Specimen. The specimen was collected in a clay 

 pit which had been opened in a shale member of the Pottsville foi'mation. 

 The specimen lying with its dorsal surface exposed is not an impression 

 only in the .soft shale, but it preserves the exoskeleton in the form of a 

 tnin, brown, chitinous film. The preservation of the specimen is excel- 

 lent except that most of the terminal segments of the walking legs are 

 missing and the fourth and fifth joints of the postabdomen are badly 

 crushed. The left pedipalp is crushed back on the tip joints of the first 

 left walking leg. The preservation of the remainder of the specimen 

 will be considered as each part is taken up for description. 



Geological Position. The specimen was found in a shale member 

 of the Pottsville formation, in the basal portion of the Carboniferous 

 series, of Clay County, Indiana. The Pottsville formation in Indiana 

 consists of a series of sandstones and shales interspersed with coal 

 seams. One thin lime-stone is present overlying the lower Minshall coal 

 located in the upper or Brazil portion of the series. The Pottsville 

 outcrop in Indiana has a northwest southeast trend upon the western 

 side of the Kankakee branch of the Cincinnati arch, extending from 

 Benton County on the northwest to Perry County on the Ohio River, 

 Clay County being near the middle of the area. The general dip of the 

 strata is to the southwest passing beneath the younger Pennsylvanian 

 formations. 



Zodlogicdl Relations of the Species. The preliminary examination 

 of the specimen and the comparison with the descriptions and illustra- 

 tions of the other American forms showed that it was a member of a 

 genus previously unknown in America. Its characters at once suggested 

 its affinity was with the Eui'opean genus Eobuthus and continued study 



''For further discussion on the morpholosy consult J. Playfair McMurrich - Textbook 

 of Invertebrate Morphology. 



