4:22 Scientific Intelligence. 



text-figures. — In this brief paper Dr. Matthew lias added one 

 more to his series of excellent and lucid phjiogenies. lie divides 

 the FelidiB into two phyla, the earliest known examples of which 

 are Oligocene, as no Eocene carnivora are known from which the 

 Oligoeene sabre-tooths can be derived. 



The distinctions of the phyla are clearly indicated in limb, ver- 

 tebra% ribs, but especially in the skull and dentition, the jjhylum 

 leading to the modern genus Fells having sub-equal canines above 

 and below and powerful biting jaws by means of which the neck 

 of the prey can be crunched. The other phylum culminates in 

 the huge sabre-tooth Smllodon, with relatively feeble lower 

 canines but with immense, curved, dagger-like upper teeth used 

 for ripping open the neck of the huge contemporaneous pachy- 

 derms the vertebraj of wiiich could not be crusiied by the jaws. 



The abundance of sabre-tooth types in early times is correlated 

 with that of the pachyderms, including the elephants, rhinoce- 

 roses, etc., while with their replacement by a swifter, thin- 

 skinned, ungulate fauna the sabre-tooths gave way to the better 

 adapted felines. Dr. Matthew denies the contention that over- 

 specialization of the canine due to "momentum of evolution" 

 was the final cause of the extinction of this interesting race, 

 though Sniilodon has often been used as evidence of the truth of 

 this somewhat doubtful factor of descent. k. s. l. 



6. An Account of the Beaked Whales of the family Ziphiidce 

 in the collection of the United States National Museum, with 

 rem,arks on some specimens in other American Museums ; by 

 Frederick W. True, Smithsonian Institution, U. S. National 

 Museum Bulletin "73, pp. 1-89 and 42 plates. — The beaked 

 whales which form the subject of this memoir are among the 

 rarest of cetaceans with the exception of the bottle-nosed mem- 

 bers of the genus Hyperoodon^ the three genera Mesoplodon, 

 Ziphius and lierardius being represented by about 100 known 

 individuals more than half of whicli belong to the first-named 

 genus. Herardius, the rarest, is known from about fourteen 

 specimens altogether. Doctor True records but nineteen speci- 

 mens of all the genera put together upon the east and west coasts 

 of the United States. These specimens are represented by skele- 

 tons or skulls sometimes supplemented by photographs and casts 

 and upon such material the main body of the work is based. On 

 pages 76-77 is a list of tlie genera and species of existing ziphoid 

 whales with their habitats. The illustrations are excellently 

 reproduced half-tones, while the text gives a very clear and ade- 

 quate knowledge of these strange cetaceans. r. s. l. 



7. Report on the Resurvey of the Maryland-Pennsylvania 

 Boundary part of the Mason and Dixon Liyie by the Mason and 

 Dixon Line Resurvey Commission, O. H. Tittmanic, Wm. 

 BuLiiOCK Clark, Isaac B. Brown. Pp. 412, with 72 plates and 

 8 figures, 1908. Published by the Maryland Geological Survey 

 as Vol. VII, William Bullock Clark, State Geologist, Balti- 

 more, 1908 (Johns Hopkins Press). — This resurvey was carried 



