946 DR F. K. C. REED ON THE 



Limestone, but differs by its more rounded shape and by the median groove near 

 the anterior end of the keeled pedicle-valve. Perhaps Rhynchonella 1 nana, Salter 

 MS.,* from Tyrone, is allied. 



Genus Atrypina, Hall and Clarke. 

 Atrypina Barrandei (Davidson) ? 



1848. Terebratula Barrandii, Davidson, Bull. Soc. Geol. France, vol. v, s6r. 2, p. 332, pi. iii, fig. 32. 

 1866. Retzial Barrandii, Davidson, Mon. Brit. Foss. Brack., vol. iii, pt. vii, p. 128, pi. xiii, figs. 10-13. 



A few small shells, 3-4 mm. long, are probably referable to this species, but the 

 specimens are not good. Hall and Clarke f referred Davidson's species Retzia ? 

 Barrandei to the genus Atrypina, of which the type Leptoccelia imbricata, Hall, 

 occurs in the Lower Helderberg Group. 



Horizon. — Saugh Hill Group. 



Locality. — Newlands. 



Genus Glassia, Davidson. 

 Glassia compressa (Sowerby). 



1839. Atrypa compressa, Sowerby, in Murchison's Silurian System, p. 629, pi. xiii, fig. 5. 

 1886. Athyris compressa (Sowerby), Davidson, Mon. Brit. Foss. Brack., vol. iii, pt. vii, p. 122, pi. xii, 

 figs. 16-18. 



Internal casts and external impressions of a smooth subcircular shell from New- 

 lands may be attributed to Glassia compressa, Sowerby, the internal characters of 

 which do not seem to have been described. In the pedicle-valve the teeth are small, 

 short slightly curved, thickened plates, nearly parallel to the hinge-line ; the 

 diductors form very narrow elongated fiabelliform weak impressions diverging at 

 about 30°, with a triangular area between them for the adductors, but not enclosed. 

 In the brachial valve the hinge-plate has the curious recurved form described by 

 Hall and Clarke | in Nucleospira, and stated by them {op. cit., p. 152) to be the 

 same in Glassia ; the horizontal suboblong portion is deeply grooved or divided in 

 its posterior half, and the hinge-plate is continued in front as a narrow low ridge 

 extending about one-fourth the length of the valve between the flabelliform 

 elongated and radially striated adductors ; the crura are short, sharp-pointed, 

 and recurved. 



Dimensions.- — Length, 13*0 mm. ; width, 14*5 mm. 



Horizon. — Saugh Hill Group. 



Localities. — Newlands, Woodland Point. 



* Davidson, op. cit., vol. iii, p. 192, pi. xxiv, figs. 26, 26a-c. 



t Hall and Clarke, op. cit., Brach., ii, p. 161. 



| Hall and Clarke, op. cit., Brach., ii, p. 142, pi. xlviii. 



