MARYLAND GEOLOGICAL SURVEY 353 



glabella there is a rather broad, shallow, concave furrow. Free cheeks 

 depressed-convex, with the eyes abruptly elevated, marked by a rather 

 broad marginal border on both the lateral and posterior margins, on the 

 inner side of which there is a rather sharply impressed furrow. Pygidium 

 small, sub-semicircular in outline; the posterior margin regularly 

 rounded ; the anterior margin straight nearly to the lateral angles, where 

 it is curved backward. Axis narrow, not reaching to the posterior margin, 

 marked by six or seven annulations. Pleurae convex, much depressed 

 below the axis, marked by five or six grooved segments, only the anterior 

 two or three of which reach the margin of the pygidium. Thorax UEH 

 known. The entire surface of well-preserved specimens is finely grami- 

 lose." Weller, 1903. 



The specimens from the basal Martinsburg shale are not as complete as 

 the types upon which the above description was based, but there seems 

 little doubt of their specific identity. 



Occurrence. MARTINSBURG SHALE (Sinuites bed). Chambersburg, 

 Pennsylvania. Trenton limestone of New Jersey. 



Collection. U. S. National Museum. 



Genus CYPHASPIS Burmeister v ' 

 CYPHASPIS MATUTINA Euedemann 



Plate LI, Figs. 12-14 



Cyphaspis matutina Ruedemann, 1901, New York State Mus. Bull., No. 49, 

 p. 62, pi. iv, figs. 5-7. 



Description. " The glabella is short, roundish, subquadrangulaf, 

 moderately and uniformly convex, sloping equally to all sides ; surrounded 

 by deep dorsal furrows and an equally deep frontal furrow. Three pair's 

 of glabellar furrows are discernible, the first two faint, short and oblique, 

 the third semicircular, extending to the occipital furrow, and separating 

 a pair of less convex lobes, which extend a little beyond the lateral margin 

 of the first and second lobes ; the broad border slopes steeply to a narrow 

 rim, somewhat upturned at the margin. The glabella and rim are 

 apparently completely smooth, but show under the glass fine transverse 



