Vol. 65.] THE ROCKS OF THE TOTJRMAKEADY DISTRICT. 121 



brecciated, is entirely free from admixture -with ashy material. 

 It dips north 30° west, and has a thickness of at least 30 feet. It 

 appears to he regularly interbedded in grit. The (?) Bala grits and 

 conglomerates are seen faulted against it in the stream. 



(7) About 500 yards north-east of Gortanalderg is a strip of 

 limestone-breccia about 100 yards long. This is of the coarse type, 

 and contains many felsite-fragments. It appears to be interbedded 

 with gritty ashes. 



"We now come to a set of exposures of much more continuous 

 character, seen along the course of Stream F : — 



(8) Tour patches form a nearly continuous band, which can be 

 traced for 300 yards or more. It clearly follows the strike of the 

 associated tuffs, which at one point dip northwards at 40°. The lime- 

 stone-breccia is identical in character with the coarse type described 

 above, and consists of blocks of limestone and of felsite embedded 

 in a matrix which weathers very readily into a perfectly rotten rock, 

 but when fresh is seen to be a calcareous ashy grit, practically 

 identical in character with the fossiliferous rock at Gortbunacullin 

 and elsewhere. The limestone-blocks are, as a rule, of a horny type 

 and white or grey, but there are a few red crystalline blocks, includ- 

 ing one having a length of 2 feet. From these blocks, and chiefly 

 from the large one just mentioued, we collected the following 

 fossils (45) : — 



Acrotreta (?) hibernica, sp. nov. 

 Camerella thomsoni, Dav. (?). 

 Lingula brevis, Portl. 

 Lingula ovata, M'Coy. 

 Ort'his call/gramma, Dalm. 

 Orthis elegantula, Dalm. 

 Or this sp. 



Agnostics agnosliformis, M'Coy. 



Ckeirurus sp. 



Harpes sp. 



Ill anus bowmani, Salt. (?). 



Illcenus sp. aft', chudleighcnsis, Holm. 



Elcenus sp. 



Pliomcra. pseudoarticulata, Portl. 



Plectambonites sericea, Sow. | Pliomcra aff. fischeri, Eichw. 



Porambonites cf. intercedens, Pandei 

 Porambonites sp. 

 Strophomena antiquata, Sow. 

 Strophomena cf. retrofle.va, Salt. 

 >is aff. Mspinosus, M'Coy. 



Spharocoryphe sp. 



Primitia sp. 

 Turrilepas sp. 

 Crinoids. 



At one spot on the northern bank is an exposure showing several 

 huge blocks of limestone, one of which measures 10 by 6 feet. 

 This rock is grey and unfossiliferous, but contains numerous quartz- 

 grains. Three other considerable exposures of limestone-breccia 

 are met with before the point where the stream, on meeting the 

 road from Gortbunacullin, bends sharply south-eastwards. They 

 are all of the coarse type, and call for no special description. East 

 of this bend of the stream, however, occurs a narrow strip, trending 

 north by east, which crosses the stream, and can be followed for a 

 distance of nearly 300 yards. It is exposed at several points south 

 of the stream and in the stream-bed itself, but the best exposures. 

 are in some small excavations on the north. Here the deposit 

 consists of an upper mass of breccia of the usual coarse type, but 



