810 DR F. R. C. REED ON THE 



acuminate beak, shoulders meeting at 75°-80°. Brachial valve shorter, with obtuse 

 beak, faint traces of muscle-scars, and thin median internal septum. Interior of 

 both valves with delicate radial striae. Surface of shell ornamented with numerous 

 closely placed delicate concentric strise, of equal strength, more or less minutely 

 undulated, irregularly increasing in number, and closely set with very numerous 

 minute equal and equidistant granules which are generally arranged in obscure 

 radiating lines, particularly near the anterior end of shell ; occasionally several 

 adjoining granules in the same concentric row are fused together. 



Dimensions. — Length, 10"0, 19'0, 14'0 mm. ; width, 5'5, 11 '5, 8"0 mm. 



Horizons. — (l) Balclatchie Group; (2) ? Stinchar Limestone Group. 



Localities. — (l) Dow Hill, Ardmillan ; (2) Craighead, Minuntion. 



Remarks. — The shape of the Balclatchie specimens is closely like that of 

 L. ardmillanense, but the Craighead ones are more oval and less parallel-sided. 

 The interior is not well known. The ornamental granules are not so definitely 

 arranged in radial lines as in L. tenuigranulata, M'Coy, for the concentric lines are 

 much more marked in our shell. 



Lingulasma ? quaestor, sp. nov. 

 (Plate III, figs. 2-4.) 



1883. Lingula granulata, Phillips, Davidson, Man. Brit. Foss. Brach., vol. v, Silur. Suppl., p. 207, 

 pi. xvii, figs. 20, 21. 

 Non 1848. Lingula granulata, Phillips, Mem.. Geol. Surv., vol. ii, pt. i, p. 370, pi. xxv. 



Shell oblong ; length to width about 3:2; sides subparallel, nearly straight ; 

 anterior end abruptly truncate. Pedicle-valve gently convex, with small obtuse 

 prominent beak and shoulders meeting at about 100°-120° ; interior with posterior 

 fourth part of valve occupied by very low indistinct platform defined at front end 

 by short transverse arched ridge on each side of broad low median septum extending 

 in front of platform to about half the length of valve. Brachial valve gently convex, 

 with obtuse beak ; interior with thick low median septum commencing in front 

 of beak and extending fully four-fifths the length of valve, with traces of fan-like 

 " lateral" scars on each side of its posterior part and in front of them a pair of sub- 

 circular approximate " central " scars. Surface of valves covered with rather unequal 

 concentric lines and growth-ridges, the finer ones showing very faint granulation. 



Dimensions. — Length about 18"0 mm. ; width about 11 '5 mm. 



Horizon. — Balclatchie Group. 



Localities. — Ardmillan Brae, Balclatchie. 



Remarks. — The internal characters seem to be those of Lingulasma, though the 

 platforms in both valves are almost obsolete, especially in the pedicle-valve. 

 Since the granulations in Phillips' Lingula granulata are much coarser and the 

 interior is unknown, it does not seem advisable to refer this Girvan shell to that 

 species. 



