SiiriiiiM : ()mi(ii,(I(;\ oi iiii: I,imh(>i,.k. 37 



smooth ; no cNidcnccs exist of the glandular depression, and the 

 region is barely concave ; a minute foramen exists on each side pos- 

 teriorly. JViinu-niiis borealis has strongly marked glandular depres- 

 sions ol" a semilunar form, situated just within the smooth orbital peri- 

 pheries. A decided median groove di\idcs tlicm longitudinally, \vhi( h 

 in that species is continued on the culminar ])Ortion of the pre- 

 maxilla for a short distance. The glandular depressions terminate an- 

 teriorly in this curlew, in a notch, on either side, just behind the 

 lacrymal bones. The parietal region is smooth and globular, l)eing 

 impressed in most of the species by a longitudinal median groove, 

 most noticeable in X. argitata, less so in N'. borealis, least of all in 

 N. phcvopus. Among the chief points of interest in the basal view 

 is the form of the foramen magnum. This is nearly circular in N. 

 longirostis and N. arquata ; cordate in A'. pJuvopus. 



The condyle is small and hemispherical in all the species, and has 

 situated beyond and on either side of it, the usual vascular and ner- 

 vous foramina seen in this locality in ordinary birds' skulls. 



Two large supraoccipital foramina, of elliptical outline, exist in our 

 present subject and in N'. arcnata ; these openings are very small in 

 the Whimbril, and exist only on one side in N. borealis, as a minute 

 perforation. 



The surrounding mu.scular line of the occiput is quite strongly 

 marked in all the species ; least of all in the Eskimo Curlew. 



Within the brain-case w^e find the tentorial ridges quite prominent, 

 well dividing the various encephalic compartments. The longitudinal 

 one appears to be ungrooved by the sinus. 



Foraminal openings occur in the usual localities for the entrance or 

 exit of nerves and vessels. But little diploic tissue seems to be de- 

 posited between the tubular walls of the cranial vault, these latter being 

 quite thin, and composed of firm, compact bone. 



The curvature of the mandible is almost identical with that of the 

 upper bill or ])remaxillary. ^^'hen articulated with the skull it is found 

 to be in all the species a few millimeters shorter than the latter bone. 

 In N. loiij^irostris the rami separate and diverge from each other at a 

 point about midway between tip and articular extremity. Beyond this 

 point the mandible is in one piece, rounded beneath and with rounded 

 lateral angles above. A groove deeply marks the bone along its entire 

 course in this portion, in the median line. The rami still remain 

 rounded for some distance backwards after they separate from each 



