0Q7 

 1870.] ^'^ ' [Cope. 



Prof. Kerr, with the aid of a number of men, dug from its bed and eleva- 

 ted to the surface of the ground a large fragment of the cranium, includ- 

 ing the greater part of the left maxillary and premaxillary bones, with a 

 large part of the frontal. A large fragment of the right ramus of the 

 mandible, an otic bulla, several lumbar and caudal vertebrse, with several 

 broken ribs, were also obtained. 



These remains indicate not only a species, but a genus new to science, 

 and the largest extinct Balaenoid yet discovered. 



The principal mass includes from the posterior margin of the transverse 

 process of the frontal, to within four or five feet of the end of the muzzle. 

 The mass measures eleven feet six inches in length. The fragment of the 

 ramus mandibuh measures thirteen feet ; five feet are probably lost dis- 

 tally, and there is no trace of coronoid process at the point where it is 

 broken off proximally. The length of the restored cranium would not be 

 less than eighteen feet. This gives for the total length, estimating on the 

 basis of Megaptera, seventy-five to eighty feet. 



The orbital process is nearly in line with the maxillary, probably in con- 

 sequence of pressure when lying in an oblique position. The whole cran- 

 ium has been injured from the same cause, and the matrix usually soft, 

 formed a solid investment of carbonate of lime from the carbonic acid 

 liberated during decomposition, which required several days' labor to re- 

 move. The parietal, occipital, and other bones of the brain-case proper, 

 were not recovered. 



Description. The upper surface of the muzzle is but little decurved an- 

 teriorily. A portion of its outer margin, at the posterior part, is pre- 

 served, so that its width is knoAvn. The maxillary forms a rather thin 

 lamina, and does not present any great median decurvature, as though the 

 vomer was not prominent below. Perhaps this peculiar flatness is partly 

 due to pressure, but the premaxillary presents a similar character, which 

 is evidently normal. This element foims one margin of the mass, and the 

 question as to whether the exposed face were the outer of the right, or the 

 inner of the left bone, required some care for its solution. Anteriorly it 

 is three inches in depth, near the posterior extremity, two inches. The 

 greatest width near the middle, six inches. The margin next the remain- 

 der of the mass, is rather the more elevated ; the external somewhat 

 prominent and rounded. Beneath it a deep groove marks apparently the 

 exit of a foramen. A groove in the same line is seen at various points 

 throughout its length where exposed. This bone is thus much flatter 

 than in any of the Finner whales, and resembles more that of the right 

 Avhales. The outer face being nearly plane, it can scarcely be the vome- 

 rine face, which is concave, especially so in Baltena, for the accommoda- 

 tion of the cartilaginous axis. The foramina and grooves are equally 

 present in both these genera, on the external side ; I therefore conclude 

 that the external side of the right premaxillary is the one exposed, and 

 that the width of the muzzle includes the left premaxillary, and maxillary. 

 The suture between the latter is not distinct, owing to the presence of 

 longitudinal fractures. The width of the maxillary after the prcmaxillai y 



