55 



The extremities were described as constructed exactly as in the 

 land-tortoises, in which the form of the femur and humerus is marked 

 by peculiar characters. These bones in the fossil were of a huge 

 size, corresponding to the dimensions of the sheli. The ungueal 

 bones indicated a foot as large as that of the largest Rhinoceros. The 

 humerus was more curved, and the articulating head more globular 

 and deejDer in the fossil, from which it was inferred that it had a 

 stronger articulation, greater rotation, and that the Colossochelys 

 ■was enabled to bring its anterior extremities more under its weight 

 than is the case Avith existing tortoises. 



The affinities 'with Testudo shown in the shell and extreraities were 

 found to hold equally good in the construction of the head, of -vvhich 

 a comparatively small-sized specimen, inferred to have belonged to 

 a young or half-grown Colossochelys, was exhibited. The head of 

 the adult to correspond w'ith the dimensions of the shell, and aceord- 

 ing to the proportions furnished by a large Testudo Indica, was de- 

 duced to have been two feet long. 



There were no ascertained cervical vertebrae to afFord direct evi- 

 dence as to the length of the neck, \vhich \vas constructed in the 

 diagram relatively to the proportions of Testudo Indica. The entire 

 length of the Colossochelys Atlas was inferred to have been about 

 eighteen feet, and that it stood upwards of seven feet high. 



The generic name given by the discoverers has reference to the 

 colossal size of the fossil (^ku\o(t(t6s et \ė\vs), and the s^jecific one to 

 its fitting representation of the mythological tortoise that sustained 

 the world, according to the systems of Indian cosmogony. 



The anatomical details occupied so much of the evening, that space 

 ■w'as not left for Dr. Falconer to enter on general points connected 

 Avith the fossil, such as its possible connexion -vvith the mythological 

 fables of the Hindoos and the aera of its extinction, which -vvill form 

 the subject of another communication. 



The results of a chemical analysis of the bones by Mr. Middleton 

 were communicated, showing that they contained a very large quan- 

 tity of fluorine. Some rough sketches of the Colossochelys were 

 exhibited, etched on glass by means of the fluorine yielded by its 

 own bones. The analysis indicated the presence of 11 per cent. of 

 fluoride of calcium. 



Mr. Gould exhibited a series of Birds from Australia, coUected 

 partly by himself and partly by Mr. Gilbert, viz. : — 



Fam. CoLUMBiDJE. 



Geopelia PLACIDĄ. Geop.fūcie et gutture cinereis ; occipite, dorso 



alisque e cinereo-fuscis ; singulis plumis ad apicem nigerrimo fas- 



ciatis, alulis spuriis primanisqtie saturate fuscis, humeris subtUs 



castaneis, pectore, laterihus, et nuchd cinereis lineis angustis nigris 



crebre/asciatis, et laterihus vinaceis. 



Face and throat grey ; occiput, back and -vvings ashy brown ; each 



feather -vvith a band of deep velvety black at the extremity ; spurious 



wings and primaries dark brown ; under surface of the shoulders 



