22 Lotiis B. SmyfJi — " 



with a triangular socket between them, and a long posterior-lateral 

 tooth, with a groove above it. 



Holotype. — A specimen having the two valves attached, in the 

 collection of the Geological Survey of Ireland. 



Locality. — Common in the shales immediately overlying the 

 main limestone at North Star Colliery, 1-| miles east of Ballycastle. 



This may possibly be the species figured by W. Hind (Mon. Brit. 

 Carb. LamelL, pi. xxxix, fig. 6) as C. jJcirallela Phill. ? which he 

 suggested might be a sport. 



Protoschizodus hrevifrons, .sp. nov. (Plate III, Figs. 3a-c.) 



This species agrees with De Koninck's genus in external features. 

 No specimen was found showing internal structure, but by rubbing 

 down, from the right side, a left valve embedded in matrix, the two 

 teeth characteristic of the genus were proved. 



The following characteristics distinguish the present species : — 



1. Very short anterior end. 



2. Very pointed, and rather produced, posterior end. 



3. Postero-dorsal region, behind the oblique ridge, flattened at 

 right angles to the plane of the valve margins. 



4. Postero-dorsal margin scarcely at all compressed, so that only 

 a very slightly elevated ridge is formed. This feature is not clear 

 from Fig. 3a. Fig. 3c expresses it better. 



Holotype. — A specimen having the two valves attached, in the 

 collection of the Geological Survey of Ireland. 



Localities. — Common in the shales immediately overlying the 

 main limestone at North Star Colliery, li miles east of Ballycastle. 

 The type came from this locality. Also occurs in red shales of the 

 same horizon at Murlough Bay, on the east side of Fair Head. 



Chonefes elegans, sp. nov. (Plate III, Figs, ia-d.) 



A small Chonetes is abundant at Ballycastle, which is easily 

 distinguished from any species hitherto named. In the hope that 

 it may prove to be of zonal value it is here given a name 

 and described. 



Description. — Length of largest specimen 15"5mm., width 

 2^"5 mm. Average ratio of length to width f . Concavo-convex, 

 regularly curved from umbo to anterior margin along median 

 plane. Average convexity of pedicle valve in larger specimens 

 about 0'36 of length. Widest part a few millimetres below 

 hinge-line. About sixty specimens in seventy-four showed a more 

 or less distinct, shallow, ventral sulcus. 



Costa e fine, sharp, about twenty-five in 5 mm. on the middle of 

 the pedicle valve. They increase almost exclusively by intercala- 

 tion on the pedicle valve ; by forking on the brachial valve. 

 Concentric ornament extremely fine. 



Cardinal spines usually eight on each side of umbo. Greatest width 

 of ventral area about 1 mm., of dorsal 0"5 mm. Strongly arched 



