﻿KIMMERIDGE CLAY. 



73 



structures, the advantage of single substantive terms is exemplified by the convenience 

 and helpfulness to precise description which such terms afford, adjectively, in predicating 

 of ' parapophysial ' and ' diapophysial ' modifications. 



And if by ' capitular portion of the transverse process' Professor Huxley may mean 

 ' parapophysis,' and by ' tubercular portion of the transverse process ' ' diapophysis,' 1 I 

 have then to object that the ' dorsal vertebrae ' of Omosaurus do not all possess the two 

 kinds of processes. In the subjects of Pis. XIII and XIV the head of the rib is received 

 by a pit, not articulated to a ' capitular process.' The dorsal vertebras, of which the ribs 

 have not ' distinct capitula and tubercula,' have no ' capitular portions, or transverse pro- 

 cesses,' i. e., no parapophyses. 



In reference to Professor Huxley 's " Character No. 2," I submit that a Saurian with 

 sacral vertebras reduced to two in number is not a Dinosaurian. 



" 3. The chevron bones arc attached intervertebrally and their rami are united at 

 their vertebral ends by a bar of bone." 2 This is a character of Iguanodon 3 and of 

 Scelidosaurus, 4 * but not of Cetiosaurus 5 nor of Omosaurus, 6 "Char. 3" is one of a genus, 

 not of the Order Dinosauria. 



" 5. The skull is modelled upon the Lacertian, not on the Crocodilian type." For 

 the instances in which the Dinosaurian skull departs from the Lacertian, and approxi- 

 mates to the Crocodilian type, I refer to the Monograph on Scelidosaurus, 7 and to 

 that on Iguanodon. 8 These instances confirm and add to the combination of Croco- 

 dilian with Lacertian characters, propounded, in 1841, as exemplifying the more 

 generalised Saurian type of the extinct order Dinosauria. 



"6. The teeth are not anchylosed to the jaws, and may be lodged in distinct sockets." 

 The modifications of the dental system in Dinosauria concur with those of the skull and 

 jaws themselves in exemplifying the mixed or more generalised character of the group. 9 



" 7. There is no clavicle." This is probable from the crocodilian affinities shown in 

 the skull and vertebras ; and the character founded on the bone, so called, in my diagnosis 

 of Dinosauria, must be suppressed : but I have not yet seen a specimen of a Dinosaur in 

 which the scapular arch was shown in its natural condition and integrity. 



Before continuing my remarks on some of the Professor's remaining twelve characters of 

 Dinosauria, I would observe, in reference to comments upon the step taken of substituting 



1 ' Quarterly Journal of the Geological Society,' vol. xxxi, p. 426. 



2 Ibid., vol. xxvi, p. 33. 



3 Monogr. * Wealden Ileptilia,' part ii, Pal. vol. for 1854, p. 15, t. viii. [Iguanodon Mantelli) 

 ib. ib., t. i, Iguanodon Foxii (if this be not an immature specimen). 



4 Monogr. ' Fossil Dinosaur of the Lias,' Pal. vol. for I860, p. 8, t. vii. 



5 Phillips, ' Geol. of Oxford,' p. 259, fig. 2, 8vo, 18/1. 



6 Ante, p. 55, pi. xvi. 



7 Pal. vol. for 1859, pp. 7 — 14, pis. iv, v, vi. 



8 Pal. vol. for 1873, ' Iguanodon,' pp. 4—12, pi. i, fig. 9 ; pi. ii, figs. 1—15. 



9 'Odontography,' pp. 246—254, 269—272, pis. 62a, 70, 70a, 1840. 



