G. GENERAL NATURAL HISTORY AND ZOOLOGY. 297 



of the embryo in the blastoderm. In reptiles, birds, and 

 mammals the embryo occupies a central position in the 

 blastoderm, and not, as in Pisces and Amphibia, a peripheral 

 one at its edge." Journal of Anatomy and Physiology^ 

 July, 1876. 



NEW HAND-BOOK OF PALEONTOLOGY. 



ZittePs hand-book of Paleontology will be welcomed by a 

 large class of students who need something broader in scope 

 than " Science Primers," and yet without the elaborate de- 

 tail of special memoirs. The division of Palsephytology is 

 undertaken by Professor Schimper. But one part of the 

 work, which is to be completed in two volumes, is yet pub- 

 lished ; this, however, gives abundant promise of its excel- 

 lence, when complete, as a student's text-book. The illus- 

 trative wood-cuts are worthy of highest praise; and in this 

 first part are chiefly devoted to the Rhizopoda. Though in 

 some points the classification and treatment of the Foraminif- 

 era are open to criticism, yet this does not affect the general 

 usefulness and value of the work. 



THE SIBERIAN MAMMOTH. 



In his journey up the Yenisei River, Nordenskjold passed 

 through the country where remains of the mammoth abound; 

 the teeth forming an important article of commerce. They 

 are also believed to occur on the tundras. The larger parts 

 of the skeleton are known to be very rare, and still rarer, 

 mammoths with flesh, hide, and hair yet remaining. It was 

 on the peninsula between Obi and Yenisei that the great 

 mammoth deposit discovered by Schumachofl" occurred, and 

 in the neighborhood of the same place was found the mam- 

 moth which gave occasion to Schmitt's expedition. 



SUMMARY OF MARSH's RECENT DISCOVERIES. 



In a lecture by Professor Marsh to the graduating class 

 of Yale College, delivered in the new Peabody Museum, he 

 gave a brief resume of his investigations of the fossil verte- 

 brates of the Rocky Mountain region, referring more partic- 

 ularly to the cretaceous and tertiary formations. He states 

 that within the past six years these investigations have 

 brought to light more than three hundred fossil species of 



V o 



