1908.] NATURAL SCIENCES OF PHILADELPHIA. 25 



Leaving out of consideration for the moment the rostrum originally 

 .assigned to Priscodelphinus grandcevus (Case's PI. 15, fig. 1), I would 

 remark that the restoration of neither of the other two beaks appears 

 to me satisfactory, and that the figure published by Cope in 1890 is 

 even less so. As regards the latter, by adding a portion from the 

 second beak to the posterior end of the type, Cope has, in my opinion, 

 produced a figure which does not represent any species which has 

 actually existed, and, furthermore, as the portion added is itself 

 incorrect, the erroneousness of the figure is compounded. It should 

 also be remarked that in the side view (Cope's fig. 4 (la)) the alveoli 

 are much smaller than in the restoration of the type itself. 



Cope's note on the genus Rhabdosteus, published in 1890, is as follows : 



"The muzzle reaches an extraordinary elongation, and for the 

 greater part of its length forms an edentulous cylinder, which resembles 

 the beak of the sword-fishes. The few teeth which remain at the base 

 of the muzzle are like those of Platanista, with roots compressed so as 

 to be longitudinal, and crowns compressed so as to be transverse, to 

 the axis of the skull. The R. latiradix^ Cope is not uncommon in the 

 Miocene beds of Maryland. Its skeleton is unknown. The nearest 

 approach to Rhabdosteus is made by the genus Stenodelphis." 



After repeatedly examining the type specimen (PI. VI), I am 

 satisfied that this characterization is only partially correct. 



The alveoli, as restored, are horizontal. They are nine in number, 

 -about equal in size, and situated in advance of the depression in the 

 palate in which a lozenge-shaped area of the vomer usually appears. 

 Hence, they are hardly likely to represent the posterior end of the 

 series. That the alveoli should be horizontal in the midde of the 

 series is improbable. No known cetacean has such a conformation, 

 and on anatomical grounds it appears unlikely to occur. The lower 

 (or inner) margin of the alveoli and the lower half of the various septa 

 are alone preserved, and this only on one side of the jaw. No distinct 

 trace of the upper (or outer) margin of the alveoli and septa can he 

 seen on the long rod-like superior portions of the maxillae. The narrow 

 inferior strip of the maxilla, which bears the incomplete alveoli and 

 septa (already mentioned), has been placed outside the larger piece, 

 which forms the proximal end of the palate, and parallel with it. Such 

 a combination could be justified only on the ground that the maxilla 

 had split lengthwise, and that the outer and inner pieces represent two 

 parts of one and the same bone. This is improbable, as the inferior 

 surface of the larger piece is convex, while that of the smaller piece 

 is nearly plane. The smaller piece is, in my opinion, much more likely 



