242 Fresh Water Aquarium 



tie tribe. The carapace, instead of being 

 hard and of a bone-like substance, forms a 

 hat, elastic, leathery shield of a broad oval 

 shape, the widest part being about one- 

 third of its length from the tail. In color 

 it is a light olive green or brown. Large 

 spots of a slightly darker shade than the 

 carapace, surrounded by a deep brown bor- 

 der, are placed on both sides of a clearly 

 defined ridge, or keel, starting at a little 

 distance from the head and running to about 

 the center of the shield. As the spots ap- 

 proach the margin they grow smaller and 

 smaller, until the light center disappears al- 

 together, so that nothing" but the brown 

 color remains. A narrow yellowish border 

 runs around the margin, starting as a line 

 in front and broadening gradually towards 

 the tail end. Xo sign of plates is visible. 

 The surface of the carapace is finelv, but 

 sharply, granulated, so that it appears sandy 

 to the touch. The plastron is connected 

 with the carapace by a broad band, leaving 



