22 PKOCEEDINGS OF THE GEOLOGICAL SOCIET T. [NoV. 9, 



The fossils are confined to the bed of Exogyra conica ; tlds fossi- 

 liferons band preserves a medial position in the zone, as indicated 

 in the foregoing section (Ko. 9), throughont the district. Using this 

 band as a safe guide, I have traced the Glauconitic Sands from Larne, 

 around the Island Magee to Whitehead, Woodbnrn, Carmoney, &c., 

 to Colin Glen — a line- section of twenty-four miles. 



The rock is not used economically, though the employment of the 

 sands as a dressing for lands has been suggested. The phosphatic 

 nodules in the bed occur in too small a quantity to be available for 

 the purpose that such concretions are usually applied to ; they occur 

 rather as a substratum to the fossil-bed, yet many of the organic 

 remains are of the nature of casts in the phosphatic material. 



It is a water-bearing deposit, though few springs of any impoi-t- 

 ance arise upon it. 



This zone has yielded thirty-six species, which, with very few 

 exceptions, are confined to it. Most of them were obtained at 

 Whitehead, during the construction of the railway to Lame; the 

 other localities, excepting Woodbuxn, are apparently less fossili- 

 ferous, probably because they have not been wrought to such an 

 extent, on account of the difiiciilty of exploiting the bed. 



This lith ©logical zone is without doubt the "Glauconous Sand " of 

 Portlock, and the fossils of it are indicated in his list by 63 ; these 

 are identical vnth those I have found in this stratum in the neigh- 

 bourhood of Belfast. 



In the following list are some of the more important species, 

 placed according to their value : — 



Area carinata, Sow. 

 Belemnites ultimus, D' Orb. 

 Ammonites varians, Sovk 

 Peeten virgatus, Nils. 

 Ditrupa deformis, Lamarck. 



Exogyra eoniea, var. laevigata, 



Sow. 

 Peeten oi'bicularis, Mant. 



Dutemplei, D' Orb. 



Avicula lineata, Boem. 

 Peeten quinquecostatus, Sow. 



The Glauconitic Sands I formerly regarded as of the age of the 

 Gault, rather from their marked persistency and restricted organic 

 contents than from the affinity of their species to those of the Gault. 

 These sands pass up into grey marls at Woodbnrn and elsewhere. , 

 I find the same lithological features to appertain to the basement- 

 beds of the " etage Cenomanien " in Kormandy, having observed the 

 glauconite-sands underlying grey and brown marls dashed with 

 green grains, the lower passing up into the higher, from Caji de la 

 Heve to Auberville. This similarity is further increased by the 

 fossil contents. I am therefore justified in concluding that no re- 

 presentative of the Gault occurs in Ireland. 



b. The Grey Marls and Yellow Sandstones with Chert. — The 

 marls of Woodbnrn (see section, p. 21) have the same characters as 

 far westwards as Cave Hill ; they contain but few species of fossils, 

 and are of limited thickness. To the east of Woodbnrn, as at White- 

 head and around the shores of Island Magee, they are brownish-yellow 

 argillaceous sandstones with cherty masses. In the western part of 

 the district, from Carr's Glen to Colin Glen (see section, p. 25), the 



