182 report— 1846. 



ichthyic development. Cuvier has applied the term ' pterygoi'de interne' 

 to another part of the diverging appendage of the palato-maxillary arch, 

 which part, I concur with Dr. Kdstlin in regarding as homologically distinct 

 from the ' entopterygoid' of fishes. For the part in question, viz. the ' os 

 transverse' of Cuvier in the skull of fishes (24, fig. 5), and its homologue in 

 reptiles, which he calls ' pterygoidien interne' (24, fig. 22), I retain the term 

 'pterygoid' ( pterygoideum, Lat.), meaning pterygoid proper: and to the 

 bone which Cuvier calls 'transverse' in reptiles ('24', fig. 22), I apphy the 

 term ' ectopterygoid' (ectopterygoideum, Lat.) ; but this, as the table demon- 

 strates, does not signify Cuvier's ' os transverse' in the skull of fishes. En- 

 topterygoid, pterygoid and ectopterygoid, have, therefore, both the advantages 

 of substantive terms, and of being applied steadily each to a distinct bony 

 element. The ' herisseal' of Geoffroy, like the ' pterygo'ide interne' of Cuvier, 

 means one thing in a fish and another in a crocodile ; Geoffroy has also en- 

 cumbered the latter bone with a third synonym. ' Malar' (nialare or os malce, 

 Lat.) is preferable to 'jugal,' because Cuvier applies that name to one bone 

 in a fish, to another in a mammal, and to two essentially distinct though 

 coalesced bones in a bird. Malar is also the name most commonly applied 

 by English anthropotomists to the bone, to the true homologue of which I 

 would restrict its application throughout the vertebrate series. 



With regard to the 'squamosal' (squamosum, Lat. pars squamosa, &c, figs. 

 22-25, 27), it may be asked why the term ' temporal' might not have been re- 

 tained for this bone. I reply, because that term has long been, and is now uni- 

 versally, understood in human anatomy to signify a peculiarly anthropotomical 

 coalesced congeries of bones which includes the ' squamosal' together with the 

 ' petrosal,' the 'tympanic,' the 'mastoid,' and the 'stylohyal.' It seems prefer- 

 able, therefore, to restrict the signification of the term ' temporal' to the whole 

 (in Man) of which the ' squamosal' is a part. To this part Cuvier has unfor- 

 tunately applied the term 'temporal' in one class and 'jugal' in another : and 

 he has also transferred the term ' temporal' to a third equally distinct bone in 

 fishes; whilst to increase the confusion, M. Agassiz has shifted the name to a 

 fourth different bone in the skull of fishes. Whatever, therefore, may be the 

 value assigned to the arguments which will be presently set forth, as to the spe- 

 cial homologies of the ' pars squamosa ossis temporis,' I have felt compelled to 

 express the conclusion by a definite term, and, in the present instance, have 

 selected that which recalls best the accepted anthropotomical designation of the 

 part, although 'squamosal' must be understood and applied in an arbitrary 

 sense, and not as descriptive of a scale-like form, which, in reference to the bone 

 so called, is rather its exceptional than normal figure in the vertebrate series. 



The term ' tympanic' (tympanicum, Lat.) appears to have received the most 

 general acceptance as applied to that bone which the early ornithotomists have 

 called 'os quadratum' and ' os intermaxillare,' (fig. 23, 2s) and which as a pro- 

 cess of the human temporal, sometimes called 'external auditory,' supports the 

 tympanic membrane (fig. 25, 2s). 'Caisse' is the French and 'pauke' the Ger- 

 man equivalent ; but Cuvier more commonly uses the phrase ' os tympanique.' 

 The chief point, in reference to that term, as applied by Cuvier, from which 

 I find myself compelled to dissent from the great and ever- to-be-revered 

 anatomist, relates to the view which he has taken of the large and long pe- 

 dicle which supports the mandible in fishes, and which, in that class, is sub- 

 divided into sometimes two, sometimes three, and commonly into four pieces. 

 I regard this subdivision of the elongated supporting pedicle as explicable 

 chiefly, if not solely, by reference to a final purpose, viz. to combine strength 

 with a certain elastic yielding and power of recovery, in the constant and 

 powerful movements to which it is subject in the transmission of the respi- 



