DTCEANOCERA. Q1 



Ruminants, very unlike the deciduous horn of the Deer— show- 

 ing the true affinity of the genus to the Antelope and Goat with 

 which It has usually been associated. It indeed only differs from 

 the normal structure of that of the animals of this group in the core 

 being covered with a case formed of agglutinated hair, which falls 

 off annually, and is rciilaced by another case formed between its 

 cavity and the outer sm-face of the core. The surface of the core 

 is covered with a vascular skin, which secretes this deciduous coat 

 of agglutinated hair, like the vascular coat that secretes and gradu- 

 ally enlarges and thickens the horny permanent case of the horns of 

 Oxen, Sheep, and Goats. 



It is to be observed that the horny case of the core of all these 

 animals is formed of agglutinated hair ; but the hairs of the horns 

 of the Oxen, Sheep, &c. are more closely agglutinated and regularly 

 placed, forming a denser substance than the porous horny case of 

 the Prongbuck, in which the several hairs of which it is composed 

 are to be seen by the naked eye, and some of them projecting beyond 

 its surface. 



I think the above observation proves that the Prongbuck is 

 more nearly allied to the typical hollow-horned Iluminants, with 

 which it has been placed, than to the deciduous-horned Deer' with 

 which Mr. liartlett proposes to unite it. Indeed it only differs from 

 them in the outer case of the horn being porous and formed of 

 loosely agglutinated or, rather, felted hairs, and in the case being 

 deciduous and renewed annually, instead of being permanent and 

 strengthened by internal laminae so as to form a hard horn. 



There is no doubt that this peculiarity of the structure and deri- 

 vation of the sheath, or rather case, of the horns affords a very good 

 character to separate the Prongbuck from the other hollow-horned 

 Kuminants ; and I suggest that it should be formed into a fiimily, 

 which should be called Antilocapridjd, of equal rank with BovidJ 

 and GiEAFFiDiE, between which families it ought to be placed 

 (Gray, Ann. & Mag. Nat. Hist. 1866, xviii. pp. 323-326.) 



After my notes on this family were written and the manuscript 

 sent to the printer, I heard that Dr. Sclater had made some observa- 

 tions on the genus at the British-Association Meeting at Notting- 

 ham. _ I am very glad to find that Dr. Sclater agrees with me in the 

 necessity of forming the genus into a peculiar family. 



Dr Sclater has adopted Dr. Suudevall's division of the Ruminants 

 into two groups, according to the form of the foot ; but I think his 

 change of Sundevall's term DigH'i>jrada into Phalcnujirirada is to be 

 regretted, as adding a useless synonym. 



There is no doubt that the form of the placenta is an interesting 

 physiological fact; but I doubt its applicability to zoological classi- 

 fication. It is only to be observed at one period of the animd's life, 

 and is only known in a very few species : for example, I am not 

 aware that it is known in Antilocapra, the genus under considera- 

 tion ; and if it differs in two genera so nearly allied as Trac/uJus and 

 Moschus, which many modern zoologists consider specie's of one 

 genus, what right have we to assume that it is similar in all the 



