47G BRITISH FOSSIL REPTILES. 



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 

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

 other toes. These obviously subserve the pm'poses 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, PL 17) of 

 Dimorphodon macroiiyx. 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 Harder, Esq., jM.R.C.S., of 

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

 (PL 16), and displayed the vertebra3 and bone-tendons of a long and stiff tail 

 (PL 17, cd.). 



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 (PL 16, 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, a) were truly 

 caudaL with similarly associated bone-tendons, as, indeed, Vo7i Meyer had recognised 

 after the discovery of the caudal structure of his Bamphorhynchis: The specimen 

 now to be described of the entire tail, as represented by its petrifiable parts, I conclude, 

 from the identity of character of some of its vertebrse with the three shown in PL 

 10, 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. 15 and 10, and, no doubt, 

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

 which is single and slight ; and it includes upwards of thirty vertebrae. These vertebrae, 3 



' " Cuvier, Wagler, unci Goldfuss lassen den Fuss aus fiinf ausgebildeten Zelien bestelien ; in alien 

 Pterodactyln liabeich aber nie mehr als vier solchen Zelien uud hochstensnoch eineii Stummel voigefunden." 

 Von Meyer, op. cit., p. 20. But see ' Osseniens fossiles,' 4to, torn, v, pt. ii, p. '3,7A — " Le cinquieme reduit 

 a nn leger vestige," &c. 



^ " Beitr'age zur naheren Kenntniss fossiler Reptilien," in Leonliard und Bronn's ' Xiues Jahrbucli fiir 

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



