HARD WICKE'S S CIENCE - G O SSJP. 



29 



nearly as many genera. No case is recorded of 

 more than one of these animals having been observed 

 in one place at a time, and their habits are almost 

 absolutely unknown. . . . This comparative rarity 

 at the present epoch," he farther says, "contrasts 

 greatly with what once obtained on the earth, 

 especially in the period of the deposition of the Crag 

 formations, and leads to the belief that the existing 

 Ziphioidsare the survivors of an ancient family which 

 once played a far more important part than now 

 among the cetacean inhabitants of the ocean, but 

 which have been gradually replaced by other forms, 

 and are themselves probably destined ere long to 

 share the fate of their once numerous allies or pro- 

 genitors." 



The members of the group may be distinguished 

 at once by the absence of functional teeth in the 

 upper jaw : those in the lower jaw are always 

 quite rudimentary, with the exception of one, or 

 occasionally, two pairs. These may be largely de- 

 veloped, especially in the male sex, and are placed, 

 generally, well forward. The blow-hole is sub- 

 crescentic, and a pair of remarkable furrows occur 

 in the skin of the throat, almost in the form of the 

 letter V, the point directed forward. The skull 

 presents a remarkable appearance in the genus 

 Hyperoodoti) caused by the enormous maxillary 

 crests which produce the peculiar conformation of the 

 head in the living animal, originating the trivial name 

 "Bottle-head." The common Beaked Whale, or 

 Bottle-head (Hyperoodon rostratus, Chemnitz), is 

 of frequent occurrence in the North Atlantic, and 

 generally visits our shores in autumn, sometimes 

 ascending the estuaries of rivers : it has been taken 

 several times at the entrance to the river Ouse. It is 

 solitary in its habits, more than two are never met 

 with in the same place, and in that case it is often the 

 old female and heryoung one : the old male is said to 

 be very shy and rarely secured. In September, 1877, 

 an adult female, 24 ft. long, was taken in the Menai 

 Straits ; it was accompanied by another, probably 

 its young one. The colour is black above, the 

 under parts being lighter : the two teeth in the 

 lower jaw are generally hidden in the gum. Its 

 food consists of cuttle-fish, the remains of great 

 numbers of which have been found in its stomach. 

 Another species of Hypcroodon, H. latifrons, has 

 occurred three or four times on the British coast ; 

 it has also been taken in Greenland. Very little 

 is known about it as a species, and that only from its 

 bones : it is supposed to attain a greater size than 

 II. rostratus, probably upwards of 30 ft. 



Cuvier's Whale {Ziphius cavirostHs, Cuv.), 

 another of this remarkable group, has been met with 

 once on the coast of Shetland, and it, or its remains, 

 have been found about five or six times in other parts of 

 Europe, and also, it is believed, at the Cape of Good 

 Hope, and the east coast of South America. It has 

 two teeth, one on each side the lower jaw, close to 



the extremity. Cuvier established the genus Ziphius 

 in 1825, from a fossil skull found on the coast of 

 Provence, in 1S04, which he believed at the time to 

 belong to an extinct animal. 



( To be continued.') 



STRUCTURE OF SAND-HILLS. 

 By W. B. Grove, B.A. 



LAST summer I had a very good opportunity of 

 examining the structure of the dunes on the 

 Lancashire coast. A copy (fig. 15) of a sketch, made 

 on the spot, may be interesting, as I can find none 

 in our common text-books which give an accurate 

 idea of it. It was taken from a natural section of a 

 hill about 14 feet high, half of which had been neatly 

 blown away by the wind. The irregularity of the 

 bedding, represented by the darker lines, is due to 



Fig 



Section of Sand-dune, Lancashire. 



changes in the direction of the wind, which, after 

 depositing a stratum, often sweeps away a part of 

 it ; and then, after another change, deposits fresh 

 material on the new surface. As the successive 

 laminae conform accurately to the varying outline of 



Fig. 16. Sandstone Cliff, Suffolk (after Lyell). 



the surface on which they are deposited, a series of 

 irregular beds is thus produced. This is often called 

 false-bedding. The same name is also applied to 

 diagonal stratification, in which the planes of the 

 lamina of sandstone are oblique to the plane of strati- 

 cation, as seen in fig. 16. But this latter structure 

 can only be formed, I believe, when a current of 

 water, carrying coarse sediment, meets with a sudden 



