112 Morgan Expeditions. 



ing at first at an angle of about 120°, and curving moderately and regularly ; 

 posterior lateral angle on either side produced backward in an acute 

 spine. On each side of the frontal lobe the margins sometimes form 

 nearly straight lines. The entire margin forms a curve, nearly equal to 

 half an ellipse, in which the relation between the two diameters is 

 about as 2 to 3. A specimen rather below the medium size measures : 

 greatest length, 14-5 mm ; greatest width, about 20 mm . A larger specimen 

 has a length of about 21""". 



Glabella very prominent, slightly flattened on top, bounded by deep 

 axal furrows, sub-pentagonal in outline, and rounded or sub-angular in 

 front; widest just back of the middle of the frontal lobe, or at about 

 one-third the length of the glabella from the front. Thence backward 

 the glabella narrows regularly, the width at occipital furrow being a 

 little more than half the length of the glabella. Frontal lobe rounded 

 or sub-angular at front and sides and very convex, curving strongly 

 downward toward the margins of the head, and sometimes obliquely 

 flattened on either side in front. Its length equals about the united 

 length of the four succeeding pairs of lobes, and a little more than two- 

 thirds its own width. Frontal furrows wider than middle and basal 

 furrows. Originating at a distance from the front equal to about one- 

 third the length of the entire glabella, they run inward and backward 

 at a strong angle, terminating near the middle of axis. They reach a 

 little more than one-third across the glabella. Upper and middle lobes 

 wider and more prominent than the basal lobe. Middle furrows situated 

 at a distance from the front equal to about 3-5 the length of glabella, 

 deep and rather narrow, perpendicular to axis, and extending inward 

 quite as far as the frontal furrows. Basal furrows deep, curving a little 

 forward, and reaching to about one-third the distance across glabella, 

 or slightly farther than do the middle furrows. Basal lobes narrow 

 and much less prominent than the other lobes. Occipital furrow deep, 

 broad and rounded. Occipital ring broad, strongly arched vertically 

 and sub-angular behind. The highest part of the glabella is situated 

 at a point about between the middle furrows. On the median line, 

 and slightly in advance of frontal furrows, is a minute, more or less 

 distinct depression, usually more marked in the internal cast. 



Limb forming a blunt, rounded or sub-angular projection in front of 

 glabella, but narrowing down to a mere line before reaching the axal 

 furrows. Cheeks very convex, with a strong convex slope toward the 

 margins ; slope toward neck and axal furrows abrupt. The limb increases 

 rather rapidly in size going backward from the axal furrows, being sep- 

 arated from cheek lobe by a well defined, broad furrow. The occipital 

 furrow is inclined slightly backward, and is deep and well defined, not 

 being extended into the nuchal spine, which last is short, acuminate 

 and not differentiated from cheek. Length of spine, measuring from 

 angle formed by lateral and occipital furrows, equal to about half the 

 length of glabella. Spines directed slightly outward. Posterior mar- 



