OSTEOLOGY OF THE PIGMY WHALE. 103 



forms the margin of the orbital cavity, is ver}- broad and short relatively to its length. 

 It is, in fact, constructed precisely on the same plan as that of the frontal in the genus 

 Salmnoptera. 



Viewed from above the orbital portion of the frontal bones is decidedly squarish in 

 outline. The length of the anterior side, that to which the maxilla is attached, is 

 pretty nearly the same length as the side which overhangs the actual orbit. The 

 frontal extends so far back that when the skull is looked at from above there is no gap 

 to be seen between the frontal and the squamosal. In the skulls of both Baloena and 

 Balcenoptera this is not the case ; and they are always, and properly, figured as showing 

 a large vacant space between the edges of the two bones mentioned. Otherwise the 

 general outline and indeed the proportions generally and the mutual angles of the 

 borders of the frontals of Neohalcena are almost a replica of those of the Rorqual, and 

 correspondingly distinct from those of Salcena. It will be observed from an inspection 

 of the drawing exhibited (PI. VIII. fig. 1) that a forward process of the frontal indents 

 the maxilla, that bone having a corresponding concavity upon its anterior edge which 

 receives the convexity of the frontal. To the inside of this the maxilla extends 

 forwards for a short distance until it is stopped by the median part of the frontal bone, 

 with which it articulates. The convexity thus formed upon the frontal is not, 

 however, very deep. When we compare these conditions with the corresponding ones 

 in Balcena and Balcenoptera, we find that NeobalcBna is somewhat intermediate, with 

 a stronger resemblance to Balcena. In the Rorquals the maxilla extends for a long 

 way forward, while in Balmna the edge is nearly straight. Thus Neobaloena occupies 

 a midway position with respect to its two allies ; but it is decidedly nearer to Balcena 

 than to Balcenoptera. 



Lodged between the frontal behind the maxilla in front is the small lacrymal hone 

 (PL IX. fig. 1, L.), which is thin and plate-like. It presents no features of special 

 interest when compared with the corresponding bone in Balcena and Balaenoptercc. 



The premaxilloe (PI. VIII. fig. 1, P.Mx.) oi Neoha.lcBna reach right to the end of the 

 jaw, from a participation in which the maxillae are excluded. This is shown both in 

 the lateral and the dorsal view of the skull. They are thin and narrow bones which 

 preserve approximately the same diameter throughout their whole course, being only 

 slightly wider posteriorly than anteriorly. Posteriorly they are widely separated, and 

 leave a wide vacuity in the middle line of the skull above ; for the last one-third 

 of their total length they are in contact. They articulate behind with the frontals and 

 with the nasals, and, of course, along the whole length with the maxillae. The articu- 

 lation with the nasals is for nearly the entire length of those bones, and, as already 

 mentioned, the premaxillse and the frontals are the only bones which have a junction 

 with the nasals. Where they embrace the nasals they are bowed inwards. The 

 premaxillse of Balcena offer a few points of diff'erence from those of Neohalcena, but on 

 the whole agree with them more closely than do those of Balcenoptera. 



VOL. XVI. — PART ii. No. 3. — August, 1901. Q 



