148 W. B. Dwight — Recent Explorations in the 



second pair arising from the central points in the edges are al- 

 most as oblique as the first pair and quite similar, except that 

 they are slightly narrower, and considerably shorter, each one 

 extending but a third of the distance across the glabella ; the 

 third and fourth furrows are very short and slight, often barely 

 perceptible, and their direction is either directly transverse, or 

 turned slightly forward. 



Occipital furrow strongly defined at its outer extremities, 

 where it terminates in pit-like depressions, but it is narrow, and 

 very shallow toward the center. 



Occipital ring, triangular, depressed convex, lower than the 

 the glabella, very broad centrally, narrowing rapidly toward the 

 lateral terminations ; the postero-lateral margins pass directly to 

 the fixed cheeks as elevated ridges, with only a slight transverse 

 depression in the line of the occipital furrow. The occipital 

 ring terminates posteriorly in an obtuse point. No occipital 

 spine has been detected in specimens favorable for its exhibi- 

 tion if one were present. 



The facial suture anteriorly passes obliquely forward and 

 outward, in a sigmoid curve, from the anterior corner of the 

 eye ; from the posterior corner of the same, it runs nearly paral- 

 lel to the posterior margin, until it turns and cuts this margin 

 near the cheek-sjjine. 



The fixed cheeks are broad, convex, elevated, but lower than 

 the glabella ; there is a deep furrow just within the well-marked 

 palpebral-lobes ; posterior limb with nearly parallel margins, and 

 about as long as the shortest transverse diameter of the glabella ; 

 its furrow is broad and central at the inner end, but passes 

 obliquely forward, as it vanishes before reaching the extremity. 

 Front limb narrow, sloping upward from the dorsal furrow, 

 elevated and rounding over at the margin ; its contour is a curve 

 of somewhat longer radius than that of the anterior outline of 

 the glabella. Ocular ridge narrow and prominent, semicircular, 

 extending anteriorly to the glabella at a point near the anterior 

 end between the third and fourth furrows. 



Free cheeks not well preserved in specimens collected ; exclu- 

 sive of the moderately long genal spine, their form is triangular, 

 and the surface generally convex, rising towards the palpebral 

 lobes. In the best preserved specimens there appears to be a 

 narrow, flat, depressed margin, running down somewhat into 

 the spine ; from the anterior part of this margin, a deep furrow 

 extends obliquely posteriorly, and inward, till it meets the pos- 

 terior margin near the genal angle ; it thus cuts off a strip of 

 the convex portion of the cheek, which strip passes down into 

 the spine to its point. 



Hypostoma triangular, convex, well-rounded anteriorly, and 

 the curved outline extending backward for more than \ of the 



