326 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



intergenal angle beyond which it becomes more narrow and extends 

 more or less obliquely forward to join the outer border [figs, i, 

 2, 3, and 4] ; in one example a short intergenal spine occurs [fig. 

 8] ; a rounded, well-defined, shallow furrow separates the marginal 

 border from the cheeks. The plane of the marginal border is slightly 

 and broadly arched across the front, the arching or rising of the 

 border beginning opposite the longitudinal center of the eye lobe. 

 Glabella elongate with sides nearly parallel to the point of attach- 

 ment of the palpebral ridge to the slightly expanded anterior glabellar 

 lobe; the glabella is convex and elevated above the level of the 

 palpebral lobes ; the anterior lobe arches down to the level of the 

 frontal marginal rim and terminates at about the width of the mar- 

 ginal border from the inner edge of the border ; the second and third 

 lobes of the glabella are narrow and united across their ends as the 

 furrow separating them does not extend to the dorsal furrow along- 

 side the glabella ; the fourth lobe is wider than the second and third, 

 and of about the same width as the occipital furrow ; the slightly 

 oblique transverse furrows are united across the center by a very 

 shallow transverse furrow ; they terminate laterally at the dorsal 

 furrow with the exception of the second pair, which in large speci- 

 mens of the cephalon may be little more than transversely elongated 

 pits [fig. 16]. Occipital ring strong and clearly defined ; it is convex, 

 with the exception of a depressed area extending from the base of 

 the median spine outward to the end of the ring ; the efifect of this 

 in flattened specimens is to give rise to what appears to be a division 

 of the ring transversely into two parts ; a small, elongate median 

 node or short spine occurs near the posterior margin of the ring 



[fig- 3]- 



The anterior flattened rim of the palpebral lobe is joined to the 

 postero-lateral base of the anterior lobe of the glabella, from which 

 it arches back to opposite the center of the occipital ring, where it 

 is about its own width from the dorsal furrow beside the glabella : 

 its width is nearly that of the second and third transverse lobes of 

 the glabella ; the elongate central area of the palpebral lobe is 

 slightly convex and depressed beneath the level of the outer rim ; 

 the visual surface of the eye is elongate and narrow, it rises abruptly 

 from its base with a gentle outward curvature or bulging to the outer 

 rim of the palpebral lobe. The openings of the corneal lenses of the 

 eye appear to be circular when viewed with a half-inch Bausch and 

 Lomb aplanatic triplet lens, but when photographed and enlarged 

 to seventy-five diameters they have an hexagonal outline [pi. 43, 



