46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



Kogiidce has yet been identified. Cope supposed that his " Paracetus " 

 mediatlanticu^ from the Upper Miocene of Maryland was related to 

 Kogia; but an examination of the original specimen shows that it 

 really belongs near Physeter. The tooth on which Leidy based the 

 name Orycterocetus may have come from a cetacean not unlike 

 Kogia, and the same is true of some teeth of a supposed physeterid 

 figured but not named by Abel (Mem. Mus. roy. Hist. Nat. Belgique, 

 Vol. 3, p. 74, figs. 9 and 10, 1905) from the Antwerp Crag. 



Squalodo}itidce.—C\\\Q.'^y on account of their peculiar teeth the 

 squalodonts are usually regarded as constituting a special family. 

 In this position they may be allowed to remain, though it must be 

 observed that their distinctness from the living Iniidce {Inia and 

 Lipotes) does not rest at present on characters that are very satis- 

 factory or very well understood. The telescoping of the braincase 

 is of the same kind and degree as in the existing iniids, and the frontal 

 appears to share to the same extent in the formation of the lateral 

 wall of the braincase ; the orbit, as in the living animals, is situated a 

 little in front of the level of the narial passages. The ethmoid is 

 less reduced than in existing iniids. I have not seen a specimen of 

 Squalodon, nor can I find one described, in which the structure of 

 either the palatine, the pterygoid, or the basal portion of the maxillary 

 is sufficiently well preserved to show the characters needed for definite 

 classification ; but there is apparently nothing known about the fossils 

 to prove that the conditions as regards these very important ele- 

 ments of the skull dififered from that which is now found in the iniids. 

 The peculiarities of the squalodont dentition, however, especially the 

 tendency of the posterior teeth to assume a conspicuously trenchant 

 character appears to indicate a line of development which was not 

 leading directly toward any of the existing groups of porpoises. 



The genus Prosqualodon as described and figured by Lydekker 

 would appear to be a member of this family. As restored by Abel, 

 however (Sitzungsber. k. Akad. Wissensch. Wien, Math-naturwiss. 

 KL, Vol. 121, pp. 57-75, pis. 1-3, 1912), the skull is, in important 

 features, intermediate between that of Squalodon and that of Agoro- 

 phiiis. Abel describes the parietals as forming a broad band across 

 the vertex between the frontals and the occipital shield, a condition 

 not mentioned by Lydekker and not shown in his figure of the type or 

 of the specimen in London afterward studied by Abel. Such a char- 

 acter, if verified, would show the presence of a stage of telescoping 

 decidedly anterior to that present in Squalodon, and would place the 

 genus Prosqualodon in a family of its own. 



