291 



MISCELLANEOUS. 



The Development and Change in the Form of the Horn of the Gnu 

 (Connochetes guu). By Dr. J. E. Gray, E.R.S. 



Mr. Edward Gerrard, jun., has lately purchased the dead body of 

 a half-grown gnu which died shortly after it was imported. 



This animal is most interesting as showing the very great change 

 that takes place in the form and direction of the core of the horns 

 and the horns themselves during the growth of the animal. The 

 very young animal is figured by me in the ' Knowsley Menagerie,' 

 but I am not aware that the half-grown animal has ever been de- 

 scribed or figured. 



The horns in this state, instead of being bent do-mi on the sides 

 of the front of the head, and flattened at the base, as in the adult, 

 are erect, cylindrical, conical, slightly curved, rather lyriform, some- 

 what like the horn of Damalis limata, but less curved. The horns 

 are rather long, smooth, with a few indistinct rings near the base. 

 The cores of the horns are 6 inches long, conical, erect, like the 

 horns that cover them. The conical horn of this age forms the 

 conical elongated tip to the adult horn. 



At a certain age, the core and horn must be gradually bent back- 

 wards at the base, and at length they are produced and spread out 

 laterally until, as in the adult animal, they are decumbent on the 

 sides of the head, with a flattened base, recurved upward in the 

 middle, and straight and conical at the end. 



The horns on the skull of the half-grown, and especially of the 

 nearly adult animal are so unHke those of the adult, that, if they 

 had been received without the skin, it would be very excusable for 

 a naturalist to have regarded them as a distinct genus intermediate 

 between this genus and the lunated smooth-horned Damalis. 



The cores of the horns of the young animal are somewhat like 

 those of the skull of the adult Nylghau, but not angulated at the 

 base, and more erect. When the horns are more developed and re- 

 curved, as they must be in the intermediate age between the young 

 and the adult form, they must be very unlike those of any known 

 genus of hoofed animals. 



The skull of the gnu is peculiar for having the lateral wing of the 

 basisphenoid extended into a broad pointed process in the back of the 

 orbit. This process is only very indistinctly seen in the figures of 

 the skull in the Catalogue of theTJngulata Eurcipeda in the Collection 

 of the British Museum, t. 15. f. 4, 5. 



On the Development of Cypris. By C. Claijs. 



The earliest observations on the development of the Ostracoda are 

 due to M. Zenker. He found that at their birth the Cytherides are 

 already provided with their two pairs of antcnna3 and two pairs of 

 jaws, but that their abdomen is still but slightly developed and 

 bears only three little appendages in jilace of the future limbs. In 

 1865 M, Claus published some observations on the larva) of Cypris, 



