Silurian Fossils of Nova Scotia. 157 



again turning forward ; posterior furrows narrow and sliarply im- 

 pressed, each one extending about one third across the glabella 

 and curving forward at their outer extremities ; central furrow 

 linear, obscure, having a direction transverse to the axis ; anterior 

 furrow obscure oblique to the axis, linear, extending to the margin 

 of the glabella a little forward of the eye ; frontal lobe regularly 

 rounded anteriorly. A fragment of a cheek in the same associa- 

 tion is broad, produced posteriorly in a short strong spine, and 

 marked by a broad sub-marginal groove. Caudal shield somewhat 

 semi-elliptical, convex, acute behind, axis very prominent, rounded 

 and marked by about eight annulations, which are gently curved 

 backward at the extremities ; lateral lobes with six simple flat- 

 tened ribs which terminate in a thickened border, and separated 

 from the axis by a strongly defined furrow ; extremity abruptly 

 pointed. 



The glabella of this species more nearly resembles Phacops in 

 the general form and faintly impressed furrows, of which the pos- 

 terior one is conspicuous. The form of the palpebral lobe, and 

 the absence of tubercles at the base of the glabella, together with 

 the form of the caudal shield, ally it with Dalmania, and it may be 

 compared with D. Phillipsi of Barrande, but has a more pointed 

 caudal shield, and the cheek, if correctly referred, is prolonged in 

 a posterior spine.* 



33. Beyrichia pustulosa. N. sp. Fig. 19. 



Yalves unequally semi-oval, a little more than once and a half 

 as long as wide ; surface marked by three prominent ridges ; cen- 

 tral, anterior, and posterior. The central one is' a single oblong 

 oval tubercle which is directly transverse to the dorsal margin and 

 a little nearer the anterior side. The anterior ridge consists of a 

 single highly elevated, rounded or papillose tubercle near the dor- 

 sal margin, and an elongated elliptical tubercle placed obliquely 

 near the antero-ventral margin, and in older specimens sometimes 

 swelling and spreading over the margin. The posterior ridge 

 rises near the dorsal margin, and making a slightly broader curve 

 than the posterior end of the valve approaches the ventral margin 

 at the centre : the ridge is high and angular with a small prominent 



• Attached to a fragment of one of these trilobites is a small Spirorbis. 

 It is dextral, with two to three turns, and rounded concentric wrinkles 

 on the last whorl. — J. W. D. 



