1S95.] l^y [Cope. 



and the nasals are spread apart laterally in the matrix. Their lateral 

 portions are produced forwards on each side of the nares for a considerable 

 distance, as vertical plates, in a manner which I have not observed in 

 any other Balaenid. The proximal extremity of the bone has the vertical 

 laminate suture usual in the family. The bulla is oval and, viewed from 

 below, the extremities are regularly rounded, the posterior but little 

 wider than the anterior. The inferior side is regularly convex in all 

 directions and the interior edge is flattened as in various other species of 

 Cetotherium. The two lateral internal longitudinal angles come together 

 well externally on the anterior end, thus leaving a very short anterior 

 keeled edge. The fate of the angles is not visible posteriQrly, as the bulla 

 is in place, but they do not seem to come together. 



There is preserved of the right mandibular ramus .595 m. from the 

 angle forwards, and a corresponding part of the left ramus, measuring 

 .740 m. The condyles and angles of both sides are preserved. The con- 

 dyle is compressed, and the articular face presents both upwards and 

 backwards. The angle is broadly truncate, its outline a broad parallelo- 

 gram, which, when placed vertically, presents its lateral upper angle to 

 the condyle, which obliquely truncates the same. The two surfaces are 

 separated by a shallow groove for only a part of this contact ; elsewhere 

 they are continuous. The presence of a coronoid process cannot be pos- 

 itively demonstrated, owing to the position of the rami in the matrix. 

 The ramus of the left side displays its characters at the anterior extremity 

 of the fragment. The convexity of the external face, as usual, exceeds 

 that of the internal, but both are rather flat and meet above at an angle 

 which is a little less than a right angle. Foramina are very few in the 

 portion of the ramus preserved. There is a very shallow groove on the 

 internal side of the superior angle, which is pierced by a single small 

 foramen. On the external side a single foramen of still smaller size 

 pierces the external wall anterior to the position of the internal foramen 

 mentioned, and three times as far below the superior angle. The inferior 

 edge of the left ramus is preserved at a position not far posterior to that 

 just described of the right ramus. It presents an obtuse angle, indicat- 

 ing that a more acute angle exists anterior to its position. Posteriorly the 

 right ramus is rounded more broadly below. 



The characters of the ramus diff^er from those of any of the North 

 American species so far known. In S. clarkianus and C. polyporum the 

 foramina are much more numerous at the corresponding locality. The 

 form of the part is different in the ;S', expansus, C. pusillum and C. ceph- 

 alus. In O. j)olyporum and C. cephalus the form is moi'e compressed and 

 the superior edge more acute ; in the other species named it is less so. 

 There is no meckelian groove as in the G. palmatlanticum. 



The three cervical vertebrae diminish in anteroposterior and transverse 

 diameters from the first to the third. The diapophyses of the atlas arise 

 opposite to the base of the neural canal and are short. The distal end of 

 each is depressed. No tuberculum atlantis. The axis is slightly concave 



