Mr. Weaver on the Geological Relations of the South of Ireland. 17 



their course, with a dip uniformly to the southward at angles from 75° to 80°, 

 except on the northern side of the western extremity, where they partially dip 

 to the north, but at the same high angle, vertical strata probably intervening. In 

 the adjoining slate and greywacke country, both on the northern and southern 

 sides of the limestone, analogous, corresponding variations in the dip are like- 

 wise to be observed. In this limestone, organic exuviae are very sparingly dis- 

 tributed, consisting of a few bivalves with some crinoidal remains. 



(24.) In the Killarney limestone district, the southern and eastern parts of 

 Muckruss peninsula, consist of blue limestone in nearly continuous strata. 

 North and west of the continuous band, the limestone alternates with thin 

 layers of slate and greywacke slate, and still further north, where beds of com- 

 pact, fine-grained, greywacke predominate, the beds of limestone gradually 

 disappear. In the region of Muckruss mine, the limestone strata dip about 

 70° to the southward, but further south they gradually acquire as low an angle 

 as 30°. Bivalves and fragments of Crinoidea occur in the Muckruss limestone, 

 and in the adjacent slate and greywacke slate, but they are confined to a few 

 species. They are incidentally met with also in the limestone of the vicinage 

 of Killarney, being, however, rare in proportion to the greater quantity of 

 sihceous matter in that rock. Indeed, in those parts where the calcareous 

 repeatedly alternate with the siliceous beds, scarcely the vestige of a shell is 

 to be seen ; for example, in the greater part of Ross Island and in some of the 

 adjacent islands. 



(25.) It is not improbable that a connexion subsists between the Killarney 

 transition limestone and that which appears in the Brisbane quarries near 

 Millstreet, traces of limestone having been observed in the boggy tract which 

 intervenes. The Millstreet band ranges south of the Blackwater river, past 

 Clonemeen to the east of Roskeen bridge, terminating at a short distance from 

 the latter in the greywacke and slate country. In most places it is amorphous, 

 but where the strata are distinctly developed, they dip to the south, at angles 

 varying from 45° to 70°, yet subject to curvatures, corresponding with those in 

 the adjacent greywacke and slaty rocks. This limestone is generally of a light 

 colour, and it exhibits few distinct organic reliquiae, the chief or most charac- 

 teristic being a species of Avicula, assembled casually in interlaced groups, 

 forming a thin separate layer. 



(26.) The band of light-coloured limestone which ranges from the east of 

 Aglish past Tallow to Castle Lyons on the west, may be seen adjacent to the 

 first-named village, reposing on and alternating with clay-slate, both forma- 

 tions, where in contact, dipping to the southward at an angle of 45°, and con- 

 taining the Producta depressa, some Spiriferae, Polyparia, and crinoidal re- 



VOL. V. SECOND SERIES. D 



