OF THE UNITED STATES 147 



feet (Spargis coriacea). In our fresh-water turtles the toes of 

 the limbs are distinct, clawed, and the feet are usually webbed, 

 if not always so. 



In speaking of this group in his Zoology, Professor Packard re- 

 marks : " The terrapins belong to the genus Pseudemys; the pretty 

 painted turtle (Clirysemys picta Agassiz) is common in the East- 

 ern States, while the Nanemys guttatus (Agassiz), or spotted tor- 

 toise, is black, spotted with orange. In the land tortoises the feet 

 are short and stumpy. The Testudo indica of India is three feet in 

 length. The great land tortoises of the Galapagos Islands, the 

 Mascarine Islands (Mauritius and Kodriguez), and also of the 

 Aldabra Islands, lying northwest of Madagascar, are in some 

 cases colossal in size, the shells being nearly two metres (six 

 feet) in length. The fierce Mascarine species were contempora- 

 ries of the Dodo and Solitaire, and are now extinct. The bones 

 of extinct similar species have been found in Malta and in one 

 of the West Indian islands. The land tortoises are long-lived 

 and often reach a great age. Certain tortoises of the Tertiary 

 Period, as the Colossochelys of the Himalayas, had a shell twelve 

 feet long and six feet high. The turtles extend back in geological 

 time to the Jurassic, a species of Compsemys being characteristic 

 of the Upper Jurassic beds of the Kocky Mountains. (Marsh.) 



" The eggs of turtles, as those of birds, are of large size ; they 

 are buried in June in the sand, and left to be hatched by the 

 warmth of the sun. It is probable that turtles do not lay eggs 

 until eleven to thirteen years of age. The development of turtles 

 is much as in the chick. By the time the heart becomes three- 

 chambered, the vertebra develop as far as the root of the tail, and 

 the eyes are completely inclosed in their orbits. The shield be- 

 gins to develop as lateral folds along the sides of the body, the 

 narrow ribs extending to the edge of the shield. In the lower 

 forms of turtles (Chelonioidce), the paddle-like feet are formed by 

 the bones of the toe becoming very long, while the web is har- 

 dened by the development of densely packed scales, so that the 

 foot is nearly as rigid as the blade of an oar." 



During the summer of 1885 I paid not a little attention to the 

 study of a few species of our common tortoises and turtles, and 

 read something about them in the books. The ordinary land tor- 

 toise, or box-tortoise, is very abundant where I live, near Wash- 

 ington, D. C., and many of them, of all ages and sizes, fell into my 

 hands that year. Several of these I kept alive and observed their 



