54 
FOSSIL REPTILIA OF THE 
in the specimen describech pass obliquely across and beneath the four long metatarsals sup- 
porting the unguiculate clawsd 
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 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 
Dimorpliodon 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 Bmorphodon, was 
observed by the Earl of Enniskillen in the collection of Henry Harder, Esq., M.Il.C.S.,of 
Lyme Regis. It had been quarried from the same cliff as the preceding specimen 
(PI. XVIII), and displayed the vertebrse and bone-tendons of a long and stiff tail 
(PL XIX, fig. 4). 
Indications of such a tail, in which the vertebrge were associated with ossified tendons, 
were apparent, and have been noted in the description in the second specimen with the 
skull (PI. XVHI, cd) ; whereby one was able to show that the vertebras 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 MampUorhynchis?' 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 vertebrae with the three 
shown in PI. XVHI, 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 XVHI, and, no doubt, 
from an adult 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 Zelien bestehen ; in alien 
Pterodactyln babe ich aber nie mehr als vier solcben Zeben und bochstens nocb einen Stummel vorgefunden.” 
Von Meyer, op. cit., p. 20. But see ‘Ossemens fossiles,’ 4to, tom. v, pt. ii, p. 374 — “Le cinquieme reduit 
a un leger vestige,” &c. 
^ “ Beitriige zur naberen Kenntniss fossiler Reptilien,” in Leonbard und Bronn’s ‘Neues Jabrbucb fiir 
Mineralogie,’ &c., 8vo, 1857, p. 536. 
3 It bas been drawn with the neural aspect downward. 
