54 



FOSSIL REPTILIA OF THE 



in the specimen described, pass obliquely across and beneath the four long metatarsals sup- 

 porting the unguiculate claws.^ 



From the position of this exunguiculate long and slender toe, as well as from its 

 difiFerence of structure, we may infer its application to a different office from that of the 

 other toes. These obviously subserve the purposes of terrestrial locomotion, and 

 perhaps of suspension : the fifth toe I infer to have helped to support, like 

 the similarly shaped production of the calcaneum in certain Bats, the interfemoral 

 expansion of alar integument, in the way indicated in the restoration (fig. 2, PI. XX) of 

 Dimorphodon macronyx. In the habitual mode of locomotion by vigorous act of flight 

 this toe would be in action while the other four were at rest ; hence the necessity for 

 greater thickness and strength of its bones, and the size of one of the tendons, as indicated 

 by the groove in the metatarsal. Interesting, also, is it to note the analogy of this 

 'wing-toe' with the 'wing-finger,' though they be not homotypes, as shown in the 

 shortness as well as thickness of the metapodial bone and the length of the pointed, claw- 

 less, terminal phalanx. 



The fourth slab of Lias adding to our means of reconstruction of Dimorphodon, was 

 observed by the Earl of Enniskillen in the collection of Henry Marder, Esq., M.R.C.S., of 

 Lyme Regis. It had been quarried from the same cliff as the preceding specimen 

 (PI. XVni), and displayed the vertebrge and bone-tendons of a long and stiff tail 

 (PI. XIX, fig. 4). 



Indications of such a tail, in which the vertebrae were associated with ossified tendons, 

 were apparent, and have been noted in the description in the second specimen with the 

 skull (PI. XVIII, cd) ; whereby one was able to show that the vertebrae in the originally 

 described specimen supposed to be cervical (Buckland, loc. cit., pi. xxvii, a, d) were truly 

 caudal, with similarly associated bone-tendons, as, indeed. Von Meyer had recognised 

 after the discovery of the caudal structure of his Bampltorkynchis? The specimen 

 now to be described of the entire tail, as represented by its petrifiable parts (PI. XIX, fig. 

 4)^ I conclude, from the identity of character of some of its vertebras with the three 

 shown in PI. XVIII, c d\ and from the discovery of this specimen in the same formation 

 and locality, to belong to Dimorphodon macronyx. 



The series of caudal vertebrae, to judge from the size of the anterior ones, comes from an 

 individual as large as that represented by the fossils in Pis. XVII and XVIII, and, no doubt, 

 from an adidt or full grown one. This series is 1 foot 9 inches in length, following the curve, 



1 " Cuvier, Wagler, und Goldfuss lassen den Fuss aus fiinf ausgebildeten Zehen bestehen ; in alien 

 Pterodactyln habe ich aber nie mehr als vier solchen Zehen und hocbstensnoch einen Stummel vorgefunden." 

 Von Meyer, op. cit., p. 20. But see 'Ossemens fossiles,' 4to, torn, v, pt. ii, p. 374 — "Le cinquieme reduit 

 a un Icger vestige," &c. 



'-^ " Beitrage zur naheren Kenntniss fossiler Reptilien," in Leonhard und Bronn's ' Neues Jabrbucb fiir 

 Mineralogie,' &c., 8vo, 1857, p. 536. 



3 It has been drawn with the neural aspect downward. 



