A COXTEIBUTIOX TO THE LoWER DEVONIAN FAUNAS OF MARYLAND 45 

 Genus COR DAN I A Clarke 



Cord AN I A cyclurus (Hall and Clarke) 

 Plate LXXXIX, Figs. 5, 6 



PJiaethonides cyclurus Hall and Clarke, 1888, Nat. Hist. N. Y., Pal., vol. vii, 

 p. 137, pi. xxlv, figs. 26-28; pi. xxv, fig. 11. 



Description. — " Cephalon. The intra-siitural portion, which is the only 

 part known, indicates a semicircular outline for the head; frontal and 

 lateral areas depressed and concave; frontal margin elevated, rising to 

 the height of the glabella, broad, thickened and rounded. Palpebral lobes 

 consj^icuous. Glabella subpyriform, convex, slightly flattened above, 

 bounded by a sulcus which is strong at the side and obsolete in froiit. 

 Baso-lateral lobes strong ; antero-lateral impressions well marked. Cheeks 

 appressed and elevated along the lateral margins of the glabella. Thorax 

 not observed. Pygidium semicircular; length to width as 1 to 2. Axis 

 prominent, elevated and longitudinally arched; width less than one-third 

 that of the shield, rapidly tapering to ;in apex just within the posterior 

 border; composed of nine annulations which are transverse, rounded and 

 separated by moderately broad sulci. Pleurae evenly rounding to the 

 flattened border, and bearing seven annulations, which are strongly sulcate. 

 Border broad, depressed or flat. All the pleural annulations pass over the 

 border to its edge, where the anterior and posterior limbs are of equal 

 strength. Doublure broad. 



" The cephalon shows traces of low pustules over the glabella, and upon 

 the depressed frontal area, where they become elongate or lachrymate, 

 sometimes anastomosing, leaving elongate depressions between them ; the 

 frontal border also bears an irregular row of conspicuous tubercles. The 

 pygidium is marked by regularly arranged pustules; a median row upon 

 the axis, bifurcating at the fifth or sixth annulation, thence backward 

 continuing double until it becomes obsolete. Four rows of finer pustules 

 are also visible on the axis, two on either side of the median row. The 

 pleurae bear three or four rows of small pustules, and the interspaces of 

 the crust are minutely granulose, and punctate. The lower surface of the 

 doublure is marked by faint radiating or venate striations." Hall and 

 Clarke, 1888. 



