66 Dr. J. E. Gray on the Family Chelydradge. 



underside sliows that the tail is covered with hairs that are 

 annulatcd with brown at the base and Hack at the end, tlie 

 brown rings becoming more abundant and occupying a 

 greater part of the hairs as they approacli the end of the tail, 

 where the black tips only occupy a small part of the ends of 

 the hairs. 



The two specimens differ in the brightness of the pale bands 

 on the underside of the tail. In one the hairs are black, and 

 the bands pale and very distinct ; in the other the hair is 

 brownish black and the brown bands are indistinct and only 

 slightly paler. 



This species I have named after Mr. Aubinn, who has sent 

 many good specimens of Mammalia and birds from Fantee, 

 and is a very intelligent native collector. 



I cannot find this species noticed in the ' Esquisses de 

 Zoologie sur la cote de Guinee ' of M. Temminck ; and it is dif- 

 ferent from any of the numerous species of African squirrels 

 we have in the Museum. 



Macroxus Wilsonii, Gray, Ann. &Mag, Nat. Hist. 1867, 



XX. p. 328. 

 Hah. Fantee. B.M. 



A nomalurus Beecroftn. 

 Hah. Fantee. B.M. 



This species has hitherto been said to come from Fernando 

 Po, but I think it is very doubtful. 



IX. — Notes on the Family Chelydradce. 

 By Dr. J. E. Gray, F.K.S. &c. 



In my paper on the development of the bones of the sternum 

 of the aquatic tortoises, I regretted that I had no materials to 

 observe the change of form of the bones during growth in the 

 animals of this family. I still have to regret the same want 

 of young specimens which I could make into skeletons ; but 

 the examination of the sternum of the more adult animals 

 shows veiy great diiferences to exist in their structure, which 

 divide them into two distinct groups, which perhaps may 

 eventually be considered as families, though they bear very 

 great resemblances to each other. 



The pelvic bones are slender and elongate, but they are 

 much more elongate in the trap tortoises {Eurysterna) than 

 in the cross-sternal tortoises (Crucisferna) ; they are very 



