EURYPTERIDS FROM THE VISEAN OF EAST KIRKTON, WEST-LOTHIAN, SCOTLAND

The hibbertopteroid eurypterid genera Hibbertopterus, Dunsopterus, and Cyrtoctenus occur in the East Kirkton Limestone of Bathgate, West Lot hian. Most specimens are fragmentary and appear to have been washed in to the depositional area with plant debris and tuffaceous sediment. Ne arly all of the identifiable material can be attributed to Hibbertopte rus scouleri (Hibbert), but two isolated Cyrtoctenus combs, and a femu r comparable with Dunsopterus have also been recognised. New material of Hibbertopterus scouleri (Hibbert) reveals that the posterior legs a nd telson resemble those of the cyrtoctenids more closely than was pre viously thought. It is possible that Hibbertopterus, Dunsopterus, and Cyrtoctenus are indistinguishable except by relatively minor character istics, and that all of the material from East Kirkton Quarry might be derived from a single eurypterid species. However, associations of th e diagnostic sclerites which would demonstrate that these taxa are eit her cogeneric or distinct have not yet been found.