38 



NATURAL SCIENCE. 



burrowing ; but the chief actual work is performed by the two large 

 claws of the fore limb, while the sand is thrown backwards by the 

 hind feet, so as to completely block up the tunnel after the animal 

 has passed. The food of Notovydes doubtless consists of the small 

 invertebrate animals found in the desert sand. 



The zoological world will look forward with great interest to the 

 discovery of the mode of reproduction of this latest addition to the 

 Marsupial order. 



Although of infinitely less morphological importance than the 

 Marsupial Mole, a considerable amount of interest attaches to the 

 discovery, during the past year, of an entirely new type of Gazelle 

 from Somali-land. So different, indeed, is this animal from all other 

 gazelles that it has been described ^ as the representative of a distinct 

 genus, under the name of Ammodorcas clarkei. Our readers may be 

 aware that, with the exception of the aberrant Gerenuk [Lithocranms 

 nallen) of Somali-land, the whole of the gazelles hitherto known are. 



Fig. 2.— Feet of the Marsupial Mole. About % natural size. i. Outer aspect of left fore 

 foot. 2. Profile view of same. 3. Ittner aspect of same. 4. Upper surface of left hind 

 foot. 5. Palmar surface of same. — After Stirling. 



by common consent, classed by zoologists in the single genus Gazella. 

 As a rule, the horns of the gazelles are either lyrate or sublyrate, 

 with their tips bent inwardly. In the gerenuk, or Waller's Gazelle, 

 the horns are, on the other hand, bent forwards at their tips in a 

 distinct hook, so that they are not unlike those of the chamois, if 

 turned the wrong way forwards. There are, moreover, important 

 points of difference between the skull of the gerenuk and those 

 of the true gazelles — notably as regards the much smaller pro- 

 portionate size of the molar teeth in the former. Now Clarke's 

 Gazelle occupies a somewhat intermediate position between ordinary 



* Thomas, Proc. Zool. Soc, 1891, pp. 207-210, pis. xxi., xxii. 



