250 BRITISB GKAPTOLITES. 



in the direction of the aperture; and the apertural margins in bi-profile view are 

 approximately horizontal, but with a tendency to eversion. 



Affinities. — 0. serratus is a species of the same 



FlG. 1(59. — Glypto(<r«phts scrrntus, sp. M *■ 



nov. general type as G. tamariscus; it is, however, 



a much larger and coarser form, the distal thecas 

 are more remote, and the apertural margins in bi- 

 profile view show a tendency to eversion rather 



\ x i than introversion. 



Horizons and, Localities. — Llandovery, Birkhill 



Shales (zone of Monog. Sedgwickii). 



Proximal end, reverse aspect. Delcraig S. Scotla.iul : Beld'aig Blll'll J Dobb's LillU, etc. 



Burn, Birkhill Shales. Coll. Wood. . f . 



Associates, etc. — Glyptog. serratus is a fairly 

 abundant fossil in S. Scotland in a definite bed at the base of the zone of Monog. 

 Sedgwickii, where it occurs associated with Climacog. Tornquisti and Cephalog. cometa. 



Collection. — The Authors. 



Var. barbatus, var. nov. Plate XXX, figs. 11 a, b. 



A very remarkable variety of Glyptog. serratus has been found by Mr. Edward 

 Greenly in Anglesea on approximately the same Llandovery horizon. In this 

 ,, ,„ , , ril 1 , variety the proximal thecas are all adorned with 



i> igs. 1/0 (i anil b. — Glyptog rapt us semi- " l 



tus, var. iarhatus, nov. mesial spines, which are robust and have a graceful 



downward curvature. In addition to these spines 





there are a number of thread-like hairs which proceed 

 indiscriminately from the surface of these thecae, so 

 that the proximal end of the polypary seems, as it 

 were, to be enveloped in a tassel. 



Horizon and Locality. — Llandovery (zone of 

 Monog. Sedgwickii). 



Anglesea : Pary's Mountain. 



Associates, etc. — All the specimens of this variety 

 , at present known come from the same locality, 



a. Proximal end showing great develop- where tlie J occul ' in fair number and are associated 



IStrfp^frfPife, JuT with Mon °9- Sedgwickii and M. discretus. 



b. Distal thecas of same specimen. Collection. — Mr. Edward Greenly. 



Diplograptus (Glyptograptus) teretiusculus (Hisinger). Plate XXX F, figs. 1 a — e. 



1840. Prionotus teretiusculus, Hisinger, Leth. Suecica, Suppl. II, j>. 5, pi. xxxviii, fig. 4. 

 1881. Diplograptus teretiusculus, Tullberg, Bihang K. Svensk. Vet. Akad. Handl., vol. vi, uo. 

 13, p. 18, pi. ii, figs. 1—7. 



