MARYLAND GEOLOGICAL SURVEY 357 



CALYMENE SENARIA Conrad 



Plate LI, Fig. 15 



Calymene senaria Conrad, 1841, 5th Ann. Kept. Geol. Surv. New York, 



pp. 38, 49. 



Calymene senaria Hall, 1847, Pal. New York, vol. i, p. 238, pi. 64, figs. 3a-n. 

 Calymene senaria Weller, 1903, Geol. Surv. New Jersey, Pal., vol. iii, p. 203, 



pi. xv, fig. 23. 



Description. " Head sub-semicircular or sublimate in outline, the 

 anterior and lateral margins being more or less nearly regularly rounded, 

 and the posterior broadly sinuous, with the posterior lateral extremities 

 bluntly subangular or abruptly rounded. Free cheeks irregularly tri- 

 angular in outline, with thick, rounded, lateral margins, denned by a 

 distinct, rounded marginal furrow, which is continuous with the furrow 

 separating the anterior end of the glabella from the prominent, elevated, 

 anterior margin of the head. Facial sutures originating just in front of 

 the genal angles, passing obliquely forward and inward for a little more 

 than half the distance to the eyes, then curving inward to the base of 

 the eye-lobe, and after passing around the eyes, extending forward and 

 intersecting the anterior margin at points a little nearer together than the 

 breadth between the eyes. Eyes small and rather prominent.' Glabella more 

 prominent than the cheeks and separated from them by deep, dorsal fur- 

 rows, about as wide behind as its length, including the occipital segment, 

 much narrower in front; the frontal and three pairs of lateral glabellar 

 lobes separated by three pairs of glabellar furrows, of which the anterior 

 pair is much the faintest and shortest; each member of the second pair 

 extends about one-fourth the distance across the glabella, slightly curved 

 posteriorly, the posterior pair deeper and wider than either of the others, 

 each member extending about one-third the distance across the glabella 

 and directed obliquely backward. Occipital furrow deep and prominent, 

 connecting with the dorsal furrows and less conspicuously with the mar- 

 ginal furrows of the posterior margin of the fixed cheeks, arching slightly 

 forward at the middle of the glabella. Occipital segment well defined, 

 arching a little forward, about as high as the most prominent portion of 

 the glabella in front. Fixed cheeks convex, provided with a deep, broad 

 furrow along their posterior margin. 



