)i PKCOKA. 



The Ruminants may be divided, according to their horns, thus : — 



I. The males and generally the females furnished with a bony 

 process on each frontal bone, which is permanent during the lives 

 of the animals. 



In the BoviDJE this bony process is covered with a permanent 

 horny sheath. 



The horn (colcoceras) has the same appearance, form, structure, 

 and is enlarged in the same manner as the hoofs over the toes. 



In the ANTiLOCArEiD.E the bony process is covered with a porous 

 horny coat, which falls off and is renewed annually. 



The horn or pseudo-horn (k-omeceras) of the Ciabrit is sui generis. 

 It seems to be formed of the matted or felted hair of the skin that 

 covers the core. It loosens and falls off in the mass when the new 

 coat of matted hair is formed beneath it. The horns may be compared 

 to the annual coat of matted hair which is shed by the American 

 Bison and some other ruminants ; but in that animal the hair only 

 forms a kind of blanket, and falls oif in flakes of different sizes. 



In the GinAFFiDJS the bony process is covered with a skin like tlie 

 rest of the body, and equally permanent, and the horn {dcrmoceras) 

 covered with hair that is shed and renewed like the hair of the body. 



II. The males and sometimes the females are periodically fur- 

 nished with horns, which, during development or expansion, are 

 covered with a vascular skin coated with down, the skin falling off 

 when the horns are perfect and solidified, and the horns themselves 

 falling off at the end of the season (Cervid^). In some few the 

 horns spring from the end of a permanent elongated bony process, 

 as in the iluntjac. 



The antler (epoch eeeras) of the Deer differs from the horns of the 

 other ruminants in being a periodical development of bone, which is 

 at first covered with a hairy skin, that dries up and falls off. 



III. Neither sex provided with any horn-Hke process of the fi-ontal 

 bone, as the Musk (Moschid^), Camels, Llama (Camelidje). 



Mr. Sclater, in his paper on AntUocapra (Ann. & Mag. Nat. Hist. 

 1866, xviii. p. 40:3), proposes the following arrangement of the 

 Ruminants : — 



I. RUMINANTIA PHALANGIGnADA. 



1. Camelidf/'. 



II. RUMIXANTIA UXGULIGRABA. 



a. Placenta polycotyledonaria. Stomachus &c. 



a'. Pedes didactyli, ungvdis succenturiatis nullis. 



2. CanielopardaUdcv ; 3. Antilocapvidfe. 



h'. Pedes tetradactyli, luigulis succenturiatis duahus. 

 4. Bovidce ; 'j. Cervidcc ; 6. Mosckidtp. 



b. Placenta diffusa. Stomachus &c. (See A. Milne-Edwards, Zool. Record, 



i. p. 29.) 



7. Trafirdida. 



" Dr. Gray, referring to this arrangement, ' regrets that the author, 

 adopting Sundevall's division, changed SundevaU's term Dlgitigrada 

 into Fhalam/ir/rada.' He doubts the applicability of the form of 

 the placenta to zoological classification, reminding lis of the scanty 



