1866.] DR. J. E. GRAY ON AMERICAN TESTUDINES. 305 



May 22, 1866. 



Dr. J. E. Gray, F.R.S., V.P., in the Chair. 



Mr. P. L. Sclater, Secretary to the Society, called the attention of 

 the Meeting to a specimen of a rare American Monkey (Pithecia 

 leucocephala), figured in Audebert's ' Singes,' pi. 6. fig. 2, lately 

 added to the Society's Menagerie. The example in question had 

 been presented to the Society on the 15th instant by Mr. W. H. 

 Barton of the R. W. I. M. S. S. Wye, and was stated by that gen- 

 tleman to have been obtained from the Buck- Indians of Demerara, 

 by whom it had been brought from a locality about 300 miles distant 

 in the interior of that country. Mr. Sclater stated that this Monkey 

 appeared to be of some rarity, there being no specimen of it in the 

 National Collection. 



Mr. W. H. Flower exhibited two specimens of the Common Death' s- 

 Head Moth (Acherontia atropos), taken on board the ' Hotspur,' 

 East Indiaman, Captain Henry Toynbee, on her homeward voyage, 

 in lat. 40° 29' N., long. 15° 00' W., 260 miles from the coast of 

 Portugal, after an easterly gale : also a specimen of Sphynx convol- 

 vuli, $, which flew on board the same ship in lat. 12° 09' N. and 

 long. 21° 17' W., — the prevailing winds being westerly and northerly. 



The following papers were read :■ — 



1. Notes on some Young Specimens of Tortoises (Testudo). 

 By Dr. J. E. Gray, F.KS., V.P.Z.S., &c. 



The British Museum has lately received a number of specimens 

 of Tortoises (Testudinata), preserved in spirits, which formerly formed 

 part of Prof. Lidth de Jeude's Museum at Utrecht, in Holland. 



They are interesting as containing series showing the growth of 

 some of the species which are found in the Dutch colonies. 



Among others there are two specimens of South American species 

 of Testudo, proving that there must be two species, which differ in 

 the coloration of the head of the animal and in the general colour of 

 the shell, though the adult skulls have been regarded as all belong- 

 ing to a single species. 



This is an instance showing how important it is in distinguishing 

 species to study the animal in all its ages. A species, as in this case, 

 may be very distinct in its young state, and the characters which 

 separate them appear to gradually disappear as the animal increases 

 in age, so that the adult specimens of the two species cannot be di- 

 stinguished. 



Testudo dentictjlata. 



Thorax pale yellow ; the margin sharp, with small deep notches. 

 Nuchal plate none. Legs dark, yellow-spotted. Head pale brown ; 

 two plates over the nose oblong, large, yellow ; crown yellow-varied, 



