ON THE VERTEBRATE SKELETON. 



179 



Disarticulated mesencephalic or neuro-parietal arch, viewed 

 from behind : Cod-fish. 



malogy,' should protest against the combination of the Greek prefix to the 

 Latin noun, I can only plead that servility to a particular source of the fluc- 

 tuating sounds of vocal language is a matter of taste ; and that it seems no 

 unreasonable privilege to use such elements as the servants of thought ; 

 and, in the interests of science, to combine them, even though they come from 

 different countries, where the required duty is best and most expeditiously 

 performed by such association. 



For the same motive that suggested the term basi-occipital, viz. because 

 the anthropotomist has been 



long accustomed to hear rig. 2.. 



that and the corresponding 

 element of the sphenoid 

 bone described as ' basilar 

 processes,' I propose to sub- 

 stitute the term ' basisphe- 

 noid' (basisphenoideum,Ij&t.) 

 for the three different de- 

 scriptive phrases applied to 

 the part (5, figs. 2, 5, 19, &c.) 

 by Cuvier, for the two ad- 

 ditional synonyms of Geof- 

 froy, and for the 'sphenoi- 

 deum basilare' of Hallmann. 

 ' Alisphenoid ' (alisphenoi- 

 deum, Lat., 6, 6, figs. 2.5, 19, 

 &c.) seemed to retain most of 

 the old anthropotomical term 

 of 'alae majores,' or wings 'par excellence' of the os sphenoideum ; as 'orbito- 

 sphenoid' (orbito sphenoideum, 10, 10, figs. 3 and 20) best recalls or expresses 

 the idea conveyed by the descriptive phrase ' alae orbitales,' or 'ailesorbi- 

 taires,' often applied to the homologous bones, regarded as processes of the 

 sphenoid in human anatomy. Here, however, in reference to the alisphenoid, 

 we find the first marked discrepancy in the conclusions of the anatomists 

 who have particularly studied its special homologies. The bone which ap- 

 pears as the 'grande aile du spheno'ide' to Cuvier and Agassiz in fishes, is 

 the ' petrosum' to Hallmann and Wagner ; it is also ' rocher' (petrosal) to 

 Cuvier himself in reptiles, and is again ' grande aile du spheno'ide' in birds 

 and mammals. The reasons which have led me to the conclusion that the 

 bones so denominated, as well as the ' ptereal' and 'prerupeal' of Geoffroy, 

 are homologously one and the same, are so intimately linked with the con- 

 sideration of the true petrosal and of other elements of the anthropotomist's 

 ' temporal bone,' that I reserve the discussion of these questions until I have 

 completed the apology for the names proposed in the first column of Table I. 



The 'parietal' (parietale, Lat., 7. 7, figs. 2, 5, 19, &c.) and ' mastoid ' (mastoi- 

 deum, Lat., 8, 8, figs. 2, 5, 19, &c.) are amongst the few bones that have had 

 the good fortune to receive, originally, definite names, applicable to them 

 throughout the vertebrate series ; although the mastoid, being like the par- 

 occipital, essentially a parapophysis, loses its individuality sooner than do 

 other bones of its segment, and becomes, therefore, a ' processus mastoideus 

 ossis temporis,' in the language of anthropotomy. The homology of the 

 'parietal' has fortunately been, with a single exception, universally recog- 

 nised throughout the vertebrate subkingdom ; the exception being furnished 

 by the eccentric homologist Geoffroy, who is, as usual, inconsistent with 

 himself, even on this plainest and least mistakeable point. 



