46 A COXTEIBUTION TO THE LoWER DEVONIAN FaUNAS OF MARYLAND 



This species, as it occurs in Maryland, differs somewhat from Hall and 

 Clarke's types in that the former have a somewhat longer glabella and the 

 position of a single pair of side furrows is merely indicated by a pair of 

 depressions on the sides of the glabella. 



Occurrence. — Helderbeeg Formation, ^NTew Scotland (?) Member. 

 Cumberland. 



Collection. — George M. Koeder. 



Genus CYATHASPIS Burmeister 



Ctathaspis australis n. sp. 



Plate LXXXIX, Figs. 7, 8 



Description. — Cephalon. Semielliptical transversely; length to width 

 about as 1 to 2; genal angles (imperfect in only specimen seen) pro- 

 duced, diverging posteriorly; border smooth, thickened, a broad well- 

 defined sulcus lying concentrically within the thickened border and ex- 

 tending from base to base of the genal angles. Facial sutures originat- 

 ing in posterior margin, extending directly and very obliquely inward and 

 forward to the palpebral lobes, thence directed obliquely outward and 

 forward to marginal sulcus where they curve sharply inward and forward 

 to the frontal margin. Glabella U-shaped, moderately and regularly con- 

 vex, bounded by a deep, well-defined sulcus which widens markedly near 

 the palpebral lobes; basal lobes pyriform, slightly alternate anteriorly, 

 oblique, conspicuous; baso-lateral furrows well marked, very convex on 

 inner side, antero-lateral furrows obsolete; frontal area regularly convex 

 to marginal sulcus. 



Eyes large, very prominent, visual area semi-circular, palpebral lobes 

 small. Cheeks small, sloping steeply to marginal sulcus; a well-defined 

 furrow running from base of genal angles obliquely inward and forward, 

 almost parallel to facial suture, to posterior extremity of palpebral lobe; 

 occipital furrow narrow but sharply marked; occipital ring moderately 

 broad on axis, tapering laterally. Thorax elongate, subequally trilobate ; 

 segments thirteen ( ?) ; axis well arched, but slightly depressed medially, 

 of same Avidth to two-thirds or more of the distance from cephalon, then 



