510 



RUMINANTIA. 



vatcd posteriorly in Bovidae (c, fig. 327.) 

 and prolonged toward the occipital crest, in 

 the formation of which they apparently con- 

 tribute, a circumstance giving rise to the 

 peculiar physiognomy characteristic of the 

 group. The osseous protuberances support- 

 ing the horns, of which we shall speak more 

 particularly when describing the latter in 

 detail, take their origin in most cases from the 

 frontal bones. In the Giraffe the slight 

 eminences analogous to the osseous cores 

 are partly formed by the parietal bone, the 

 coronal suture passing directly through the 

 centre from side to side (fig. 328.) ; the an- 



Fig. 328. 



Front view of the skull of a Giraffe. (From a spe- 

 cimen in Lond. Coll. Surg. Museum.) 



terior or central eminence, situated imme- 

 diately behind the nasals, anil in part formed 

 by them, differs in no respect, save as regards 

 its position, from the other two, the elevation 

 in all instances being produced by the expan- 

 sion of the cranial sinuses beneath. There is 

 a single large supra-orbital canal, having its 

 superior outlet midway between the upper 

 border of the orbit and the central frontal 

 eminence (fig. 328.). In Cervidas generally, 

 the canal opens at the upper surface by a 

 longitudinal furrow (fig. 329.), but this is more 

 particularly marked in Bovidae ( fig. 333.). In 

 regard to the cranial sutures in Cervidas, 

 M. F. Cuvier observes that " all those por- 

 tions, such as the second half of the frontal, 

 the greater part of the coronal, and the occi- 

 pital or lambdoidal, which surround the base 

 of the core, exhibit an excessive multiplication 

 of interlineations, because the weight of the 

 horns and the shocks to which the parts are 



exposed require that the bones should be 

 firmly connected " (/z r . 329).* 



The sphenoid (Is?) articulates, except in 

 Bovidae. with all the cranial bones ; but its 

 orbitar wing, which is largely developed, is 

 concealed in great measure within the cere- 

 bral cavity, and covered by the lateral expan- 

 sions of the frontal bones. In the Camelidae 

 the pterygoid processes of the sphenoid are 

 directed vertically downwards and terminate 

 in two laminas, the external one being longer 

 und larger than the internal : the latter pro- 

 cess only makes its appearance very low 

 down, and is so closely applied to the ex- 

 ternal lamina, as to leave scarcely any trace 

 of a pterygoid fossa ; neither is there any space 

 between it and the wing of the palatine bone. 

 In this family the spheno-orbitar fissures and 

 the spheno-palatine foramina are of great 

 size. The optic canals are only separated 

 from the former by a thin osseous partition, 

 and the openings for the passage of the third 

 branch of the fifth pair of nerves are rounded 

 and placed far back The Cervidrc have the 

 posterior division of the sphenoid developed 

 into an extremely attenuated and short tem- 

 poral wing, which, nevertheless, is articulated 

 to the parietal, the lateral processes reaching 

 very far forward. The orbitar wing of the 

 sphenoid in the same family separates into two 

 divisions, one extending upwards and back- 

 wards, and also uniting with the parietal, the 

 other being prolonged horizontally forward, 

 between the frontal and palatine bones, and 

 terminating anteriorly at the border of an 

 opening which corresponds to the spheno- 

 palatine foramen. In the Giraffe the temporal 

 wing of the sphenoid is short and connected 

 by a well-marked suture to the T-shaped 

 process of the narrow lateral expansion of 

 the parietal ; it approaches very closely, but 

 is not united to the orbitar plate of the frontal 

 as has been conjectured. In the work last 

 alluded to in the foot-note it is stated that 

 the frontal and sphenoid bones are united at an 

 early period, rendering it difficult to make out 

 their limits. In the cranium of a Giraffe 

 about two years old, and at present in our 

 possession, the sutures involved in the union 

 of the above-mentioned osseous segments, 

 fortunately yet remain distinct, and in this 

 individual the orbitar wings of the sphenoid 

 do not divide into two laminae, as seen in the 

 Stags, but at the floor of each orbit they form 

 a broad, short, and triangular fan-shaped 

 plate, the centre of which is pierced by the 

 hole for the passage of the optic nerve. The 

 spheno-orbitar apertures are round and of 

 enormous size in the Giraffe : in the Stags the 

 spheno-palatine foramina are also large ; and 

 this is more especially the case in Camelo- 

 pardalis, where they lie concealed behind the 

 molar prominences. In the genus Moschus 

 the anterior sphenoid is largely developed, 

 and its wings form the greater part of the 

 posterior wall of the orbits. The body of 



* Cuvier, Lemons cl'Anat. Comp., 2 tlc edit. torn. ii. 

 p. 3GG. 



