November i, 1891] 



THE HUMMING BIRD. 



87 



bone which covered it), the left is immensely 

 developed, attaining a length equal to that of half the 

 entire of the animal, projecting horizontally from the 

 head in the form of a long, straight, tapering and 

 pointed tusk, spirally grooved on the surface. In 

 some very rare cases both teeth are fully developed, 

 as in the fine skull exhibited near the skeletons. 



Most of the largest Cetacea exhibited belong to the 

 group called " Whalebone Whales " in which a series 

 of horny plates called baleen or more familiarly 

 " Whalebone" grow from the palate in place of teeth, 

 and serve to strain the water taken into the mouth 

 from the small marine animals on which these 

 whales subsist. Four distinct types or genera are 

 represented in the collection, the Balaena or right 

 whales, of which the well-known Balaena tnysticetus 

 of the Artie seas is a fine representative. It yields 

 whalebone of the greatest value for commercial pur- 

 poses ; the Neobalaena of which very little is known. 

 One skeleton of this remarkable whale of small size 

 (less than 20 feet) from New Zealand and Australia is 

 placed on the left side of the room, near the 

 windows ; the Megaptera or humpbacks, of which a 

 skeleton is exhibited ; the Balaenoptera, containing 

 the various species of Rorquals, Fin-whales, Fin-backs 

 and the Finners or Razor-backs, which are found in 

 almost every sea. 



Among them is the most gigantic of all animals, 

 Balaenoptera sibboldi, which attains the length of 80 

 feet, and is common in the seas between Scotland and 

 Norway. Almost of equal colossal proportions is the 

 common Rorqual {Balaenoptera musculus) found some- 

 times on the English coast. The complete skeleton, 

 68 feet long, from the Moray Frith, Scotland, where 

 it was captured in 1882, shows extremely well the 

 osteological characters of this group of whales. 



Another species not uncommon on the English 

 coast is the small Balaenoptera rostrata, which 

 never reaches 30 feet in length. 



Of the family Physeteridœ, including the great 

 Sperm-whale or Cachalot (P/tyseter macrocephalus) 

 I have already mentioned the skeleton exhibited in the 

 Central Hall of the Museum. 



The order Cetacea is one of the best marked and 

 most natural of all the larger groups of Mammalia. 



In all essential characters, by which Mammals are 

 distinguished from the other vertebrated animals, 

 such as possessing warm blood, breathing air by 

 means of lungs, bringing forth their young alive, and 

 nourishing them for a time with milk, they agree with 

 the other members of their class ; the striking 

 external differences being all in relation to their 

 adaptation to an entirely aquatic mode of life. The 

 animals of this order of Mammalia abound in all 

 known seas and some species, among which 

 Platanisla gangetica and Inia geoffrensis are in- 

 habitants of the larger rivers of Central and South 

 America and Asia. 



In size the Cetacea vary much, some of the smaller 

 Dolphins scarcely exceeding four feet in length, while 

 others are the most colossal of all animals. 



With some exceptions they are timid, inoffensive 

 animals, active in their movements and very affectionate 

 in their disposition towards one another— especially 

 the mother towards the young, of which there is 



usually but one, and at most two, at a time. They 

 are generally gregarious, swimming in herds, some- 

 times amounting to many hundreds, though some 

 species have hitherto only been met either singly or in 

 pairs. 



The great commercial value of the oil, which all 

 the Cetacea yield, and the special products useful to 

 man of certain species, as whalebone, spermaceti, etc., 

 cause some to be subject to an unremitting persecu- 

 tion, which has of late greatly diminished their 

 numbers, and threatens some of the most interesting 

 species with total extermination. 



The existing members of the order are separated 

 into very distinct suborders, having important dif- 

 ferences in their structural characters, and with no 

 transitional or intermediate forms. These are the 

 Toothed Whales or Odontoceti, and the Baleen 

 Whales or Mystacoceti. 



The first suborder, Odontoceti, or Delphino- 

 idea, includes the families Physeteridae Platanistidae 

 and Delphinidae. 



The second suborder, Mystacoceti or Balaeno- 

 idea, includes the several genera of Whalebone 

 Whales. 



EAST WING. 

 GROUND FLOOR. 



Geological and Palaeontological Galleries. 



The ground floor of this wing consists, as on the 

 other side of the building, of a gallery running west , 

 and east the whole length of the wing in front, of a 

 smaller parallel gallery behind it, and leading from 

 the latter, a series of galleries running north and 

 south. The whole of this floor is occupied by the 

 collection of the remains of animals and plants 

 which flourished in geological periods anterior to that 

 in which we are now living. Some of these belong to 

 species still existing upon the earth, but the great 

 majority are extinct. 



SOUTH-EAST GALLERY. 



VERTEBRATE ANIMALS. 



Class /.—MAMMALIA. 



The cases in the South-East Gallery are devoted to 

 the exhibition of the remains of animals of the class 

 Mammalia, the great proportion of which are only 

 met with as petrifactions, or fossils, in those newer 

 layers known to geologists as the Tertiary and 

 Quaternary deposits, forming the more superficial 

 part of the earth's crust. Earlier traces of such 

 higher class of animals are comparatively rare, but are 

 met with in the Eocene formation, and a very few 

 remains of the lower type, which are extremely small 

 in size, occur in rocks of secondary age. Quite 

 recently (1889) Professor O. C. March has discovered 

 in the " Laramie " formation, in strata of cretaceous 

 age, in Dakato and Wyoming territories, North 

 America, numerous remains of small mammals having 

 close affinities with those previously known and 

 described, from strata of Triassic and Jurassic age. 



