ART. 15. A NEW GENUS OF WHALE FROM MARYLAND— KELLOGG. 5 



side. They are borne on very short condylar processes and are set 

 off from the exoccipitals by shallow concavities. The peculiarities of 

 the occipital condyles correspond more closely "vrith those of Geto- 

 therium megalophysum than with any other cetothere described by 

 Cope. In Agorofhius and Archaeodelphis *^ the condyles are much 

 more protuberant and are set off from the exoccipitals by distinct 

 necks. The articulating surfaces of the condyles are relatively 

 larger; their flattened appearance and short neck indicate that the 

 skull rests firmly upon the corresponding articular surfaces of the 

 atlas. This modification, in turn, leads one to conclude that the 

 anterior cervicals, at least, were fused together. The small mastoid 

 region for muscle attachments, taken in connection with a broad, 

 flattened, and shallow condylar surface, indicates a limited degree 

 of mobility for the head. In all probability its habits in feeding and 

 the correlated movements of the head were similar to those of living 

 whalebone whales. 



Lateral view. — The marked convexity of the cranium, the arched 

 base line, together with flattened occipital condyles, closely appressed 

 exoccipitals, and the marked ventral projection of the postglenoid 

 processes, combine to lend this aspect of the skull (pi. 3) a very 

 different appearance from that of Agorofhius pygmaeus. In this 

 specimen the highest point of the dorsal profile is formed by the apex 

 of the supraoccipital, in front of which the sagittal crest formed by 

 the parietals slopes forward to the rostrum. In Agorophius, on the 

 contrary, there is an obvious elevation of the skull at the base of the 

 maxillaries, back of which the dorsal profile is seen to extend on a 

 nearly horizontal plane to the apex of the supraoccipital. 



The zygomatic process of the squamosal is slender, tapering ante- 

 riorly ; the dorsal surface slopes gradually forward. This is in strong 

 contrast to Cetotherium rathhei., in which it is large and thickened 

 and underlaps the postorbital projection of the supraorbital plate. 

 Correlated with this difference is the form of the glenoid cavity and 

 the length of the postglenoid process. In form this portion of the 

 squamosal apparently bears a closer resemblance to C etotkeriivin than 

 to Agorophius.) Archaeodelphis, or Patriocetus^. The postglenoid 

 process is a thick plate of bone projected more backward than down- 

 ward and whose posterior face is grooved by the external auditory 

 meatus. This process is rather broad and terminates in a blunt, 

 rounded tip. The squamosal as a whole is relatively large, firmly 

 fixed to the side of the skull, and internally takes part in the forma- 

 tion of the lateral wall for the cranium. 



* Alleii, G. M., A new fossil cetacean. Bull. Mus. Comp. Zool. at Harvard College, vol. 

 6-.3, No. 1, pi., figs. 1-2, 1921. 



'^ Abel, O., Die Vorfahren der Bartenwale. Denkschr. d. Kais. Akad. Wis.sensch. math.- 

 naturw. Kl., Wien, vol. 90, pis. 2, 6, J2, 1913. 



5596— 24— rroc.N.M. vol.03 18 



