52 THE OSTEOLOGY AND MYOLOGY 



are only connected with the skull by soft tissues, and are removed from its immediate 

 vicinity ; the styliform occipital parapophyses appear to perform, as far as muscular at- 

 tachments are concerned, the office of the hyoidean plcurapophyses. 



Y. prose^icephalica. The confluence of the frontal centrum and neurapophyses with 

 those of the parietal segment, has just been noticed ; these elements are distinct from 

 their homotypes of the nasal vertebra. The neural spine, at first in lateral halves, 

 speedily consolidates into one piece, but coossifies with none of the numerous surrounding 

 parts. It is remarkable for its size, and for taking greater 23art in the formation of the 

 olfactory chamber, than in the protection of the prosencephalon. Frontal parapophyses 

 are wanting ; at leiist no post-frontals can be demonstrated, nor is there evidence war- 

 ranting the assumption that they are included, otherwise than theoretically in the 

 frontal, or a neighboring, bone. It may however, be surmised, that the su^^er-orbital 

 protuberances of the frontal bone may represent, teleologically at least, such para- 

 pophyses ; since they subserve the usual function of Ihniting the orbits posteriorly. The 

 pleurapophysis is disconnected with the other elements of this vertebra, dislocated, lying 

 between the last and the penultimate vertebrae, and pressed into the service of the organ 

 of hearing ; it is a delicate little half-ring, supporting the membrana tympani and ossicula 

 auditus. As already noted, it has no osseous union with the rest of the skull ; and even 

 its membranous attachments are of the loosest nature. No trace of separation of htema- 

 pophysis from haemal spine is usually to be observed ; nor is there any distinction of the 

 several hff>mapophysial elements that remain distinct in lower classes, and may theoreti- 

 cally be taken to exist in the present example. The haemal spine is permanently sepa- 

 rated into halves, as far as osseous symphyseal union is concerned. The frontal htema- 

 pophysis not only articulates with the distal element of the maxillary appendage, as usual 

 in mammalia, but also with the proximal element of the same ; and moreover — what is 

 a rare modification — with the parietal neurapophysis, (squamosal, malar and alisphenoid 

 thus conniving to form the glenoid cavity) ; it is not connected with its own, or other 

 pleurapophysis. 



V. rhineacephalica. The centrum, j^ermanently distinct from that of the succeeding 

 vertebra, is an attenuated osseous spiculum, only having solidity behind for articulation 

 with the presphenoid ; it is in intimate relation throughout with the enormously devel- 

 oped olfactory sense-capsule. The neurapophysis, if it have any actual existence, is ob- 

 scure, and not to be satisfiictorily demonstrated in any part of the olfactory capsule ; but 

 it may be conjectured that the vertical " septvnn nasi" represents coalesced pre-frontals. 

 The neural spine is permanently bifid, and remains distinct from surrounding bones ; like 

 its centrum, it has been subjected to longitudinal extension and attenuation, to close in 

 the upper wall of the conical muzzle. This vertebra has no diapophysis. The pleura- 

 pophysis forms but little part of the maxillary arch, though still performing its proper 

 office much more notably than does the same element of the frontal vertebra. As usual, 

 it is curiously distorted in shape, and closely wedged in between numerous elements not 

 of its own, but of two succeeding, vertebrte. The development of the nasal ha^mapophy- 

 sis corresponds with that of the frontal ; it articulates not only with its fellow, its pleura- 

 pophysis, and its hajmal spine, but also with the neural spines of its own and of the suc- 

 ceeding vertebra ; it likewise supports, in part, a mucous scale-bone and convolutions of a 

 sense-capsule ; and besides is connected, through the intermedium of two accessory appen- 



