THE REPTILES OF OHIO 157 



the rest of the body. Ahhough the young have an egg-tooth below the flexible 

 proboscis it does not seem to be used in escape from the eggs, and is dropped a week 

 after hatching. 



MuIIer found that the young were nearly circular and his measurements 

 of the carapace lengths of five newly hatched ones varied from 1% to 1 "Jiq 

 inches. His observations showed that the eggs in the nests on the island 

 hatched from July 31 through early August and that the incubation period 

 under favorable conditions was from 70 to 75 days. 



According to Cahn (1937, 183) the eggs are round and white and are 

 smaller but very similar to those of Amyda spinifera. He found that the 

 average size of 116 eggs was 22.6 mm. 



Amyda spinifera (Le Sueur) 

 Spiny Soft-Shelled Turtle 



Description. — A large turtle attaining a carapace length of fourteen or fif- 

 teen inches; females reach a considerably greater size than males. Largest 

 adult Ohio specimen ( ? ), measured 14^/2 inches in (shell) length; largest 

 male, 61/2 inches; smallest juvenile, probably recently hatched, 1 i^/ie inches. 



Carapace leathery and without horny plates. Outline oval and not much 

 longer than wide; margin entire. Shell rounded but nearly fiat; juveniles with 

 a slight vertebral ridge. Anterior margin of carapace studded with numerous 

 more or less prominent tubercles. The entire upper shell, in males, covered 

 with small tubercles which in the larger specimens feel like sandpaper. In 

 large females these tubercles usually are very fine and often confined to the 

 anterior and posterior ends of the shell. Carapace thrust well backward so 

 that its anterior end extends no farther forward than the anterior end of the 

 plastron; posteriorly it extends much farther backward than the plastron. 

 Plastron leathery and relatively small, well covering the soft parts anteriorly 

 but leaving the hind legs and tail exposed. 



Head moderately small, narrow and tapering to a prolonged and flexible 

 snout. Mandibles covered with fleshy lips. Nostrils divided by a septum 

 from which a narrow ridge, running back into the nasal passage, projects into 

 each nostril. Tail stout, the anus near the tip. Tail protruding beyond the 

 carapace in adult males, scarcely reaching the edge in adult females. Skin 

 smooth; a few scales on the limbs. Feet well webbed; five digits on each foot 

 but only the first three bearing claws. 



Carapace olive grey, marked with numerous circular black spots which are 

 largest toward the center of the shell. Margin with a narrow yellowish band 

 bordered interiorly by a nearly continuous black line. In large females the 

 circular markings break up and the pattern consists of mottled areas of various 

 shades of olive green, brown or grey. The writer has seen no adult males in 

 which the circular spots were not present. 



Plastron uniform white or yellow. Edges of underside of carapace occa- 

 sionally streaked or spotted with blackish. Head olive grey, dotted or streaked 

 with black. A yellow line, bordered with blackish, extends backward from the 

 snout through the eye to the neck. Lips yellow, spotted with grey or olive. 



