24 TBILOBITES OF GIRVAN. 



widening at sides, marked off by shallow curved occipital farrow. Fixed 

 cheeks weakly convex, broadly triangular, short, extending only halfway up sides 

 of glabella. 



Dimensions. — 



Length of head to base of spine . . 7'0 mm. 



Width „ at base . . . 15*0 ,, 



„ of glabella at middle . . .6*0 „ 



Affinities. — This species differs from A. hornet in possessing a frontal spine 

 and only one pair of furrows on the glabella, in the anterior projection of the glabella 

 and in the shortness of the fixed cheeks. From A. mammillatus it differs by the short- 

 ness of the fixed cheeks and the single pair of furrows on the glabella. A. foveolatus, 

 Angelin, 1 appears to agree in the projection of the glabella in front, the course of 

 the lateral furrows marking off the lateral lobes and the pair of basal nodules ; but 

 the latter are more obscure in our single specimen, and there is no anterior pair of 

 pits on the glabella. 



Collection. — Mrs. Gray (one specimen). 



Horizon and Locality. — Stinchar Limestone Group (Llandeilo) : Craighead. 



8. Ampyxcf. scanicus (Angelin), 1854. Plate III, fig. 1G. 



Specific Clin meters. — Pygidium broad, subtriangular. Axis nearly one third 

 the width of the pygidium, subcylindrical, very slightly tapering, with an obtusely 

 pointed end, reaching posterior margin ; composed of 7 — 8 rings of which the 

 posterior ones are indistinct. Lateral lobes gently convex, with 3 — 4 very faint 

 grooved pleurae on their surface and one strong oblique furrow marking off 

 articulating area along anterior margin. Border wide, steeply bent down, concen- 

 trically striated. 



Dimensiojis. — 



Length . . . . .10 mm. 



Width . . . . . 22 „ 



Remarks. — Two isolated pygidia from Shalloch Mill possess the above characters 

 which resemble those shown in Angelin's figure of A. scanicus? No head-shields 

 of Amjpyx from this locality have come under my notice. 



Affinities. — The shape of the axis, its distinct segmentation and non-trilobation 

 distinguish this form from A. restrains, Sars. 



( 'ollection. — Mrs. Gray. 



Horizon ami Locality. — Whitehouse Group (M. Bala): Shalloch Mill. 



i Angelin, ' Pal. Scand.', p. 80, pi. xl, fig. 2 ; ? Pompecki, ' Beitr. z. Naturk. Preuss. Pliys. Oek. 

 Gesell. Eonigsberg,' 7, p. 16, pi. iv, figs. 17, 17 a. 



- Angelin, ' Pal. Scand.,' pi. xl, fig. 10, p. 82 (Raphioplwrus scanicus). 



