62 Proceedings of the Royal Irish Academy. 



and the handsome Pcdaeopteris hibernica (Forbes). Fronds of Sphenopteris, 

 easily distinguished by its obtusely terminated leaflets, are less common. 

 In the band of coarser sandstone, mentioned above, scutes and spines of 

 the fish Coccosteus have been found in considerable quantity, together 

 with other remains referred to Asterolepis, Bothriolepis, and Pterichthys. 

 Fish- teeth are scarcer than the scutes, but a few have been found; in 

 the Dublin Museum is a specimen of a fish-jaw with two or three teeth 

 in position. The most famous fossil animal from Kiltorcan is Archanodon 

 Jukesi (Forbes), a large mussel nearly allied to the living freshwater genus 

 Anodonta ; this is the only mollusc known from the beds. 



Very few remains of Arthropoda have hitherto been found at Kiltorcan. 

 Two fragments were described and figured by Salter (1859) as portions of a 

 merostome carapace, and doubtfully referred by him to Ev.TijpUrus Scouleri, 

 Hibbert, from the Carboniferous of Fifeshire. Later (1870), Baily named 

 these and other fragments Pterygotus Mhernims ; they are probably, however, 

 referable to Eurypterus. Baily also described a Belinurus — B. kiltorcensis — 

 from two specimens which, with the types of his Eurypterus Mhernicus, 

 are preserved in the Geological Survey collection in the Dublin Museum. 

 Formerly these genera were regarded as Crustacea; but the usual practice 

 among modern zoologists is to group the orders to which they belong with 

 the Arachnida. Baily, however, briefly described (1870) some truly Crustacean 

 remains — a few Leptostracan carapaces — under the name of Proricaris 

 MacHenrici. The fossil Isopod, which we now describe, is thus the second 

 Crustacean type from the Kiltorcan beds. 



One of us visited the quarry early this year to obtain specimens of the 

 fossil ferns and mussel for our College teaching collection. The farmer, 

 Mr. T. Davis, on whose lands the quarry is situated, gave much useful 

 help, evinced interest in the search, and undertook to forward to Dublin 

 any specimens that seemed to him noteworthy. Shortly afterwards we 

 received a slab on which an impression of the dorsal surface of the new 

 Crustacean (Plate IV., fig. 2) is beautifully preserved. Another visit on our 

 part to the quarry was thought advisable, and as a result the fossil itself 

 (Plate IV., fig. 1) was secured. This had been put on one side by Mr. Davis, 

 who had recognized its nature, but thought it useless to us on account of 

 an accidental breakage. Both the specimens — which are of course to be 

 regarded as types — will be deposited in the Dublin Museum, the impression 

 in the collection of the Geological Survey of Ireland, and the fossil in the 

 general Paleeontological Collection. The greater part of the head has, 

 unfortunately, been chipped off the latter, otherwise both specimens are 

 in admirable preservation, considering the nature and age of the rock. 



