TESTUDINIDAE 357 



four stripes on the neck being especially conspicuous. The limbs 

 have pale yellowish streaks. All these markings are, however, 

 subject to much individual variation. While, for instance, the 

 half-grown creatures are distinctly agreeably coloured, often with 

 a rich brown, nicely sculptured shell, and with conspicuous orange 

 and yellow marks on the skin, the very old ones become rather 

 ugly, the prevailing colour varying more and more into dull 

 uniform pale olive-grey. 



The " Iberian Water - tortoise '' is typical of the Iberian 

 Peninsula, and extends through Morocco and Algeria far into 

 North-Western Africa. Unknown to the north of the Cantabrian 

 range, decidedly scarcer than its cousin Emys in the northern 

 half of the Peninsula, it becomes common in the south. In the 

 Alemtejo, in the lower parts of Andalucia and in Morocco, there 

 is scarcely a pool, stream, or river in. which it is not found, 

 feeding on any living thing it can master, although fishes and 

 frogs are its principal prey. When the streams and watercourses 

 run dry, during the hot and dry season, the tortoises crowd to- 

 gether into the remaining pools, which soon become stagnant 

 and filthy. But even these havens of refuge are not of lasting 

 avail. They are soon cleared of anything edible, and the stink- 

 ing water becomes dirtier and hotter day by day. Ultimately 

 the tortoises leave the pool to hide under ledges of rocks, where 

 they aestivate for months. This life in the muddy, slimy pools 

 renders these tortoises peculiarly liable to the attacks of a certain 

 fresh-water alga, which enters through the cracks in the horny 

 shields and then flourishes in the Malpighian layer, and even in 

 the underlying bone itself This becomes gangrenous in patches, 

 and the whole shell assumes a leprous appearance, hence the 

 specific name of leprosa. Everything combines in favour of this 

 destructive little alga. The tortoise, covered with mud, basks in 

 the hot sun, the ' horny shields become brittle and crack, often 

 peeling off in thin flakes. But those happy individuals which 

 inhabit permanent rivers, or pools which do not dry up, are, and 

 remain, as clean as other water-tortoises. 



G. le23rosa has a most disagreeable, offensive smell, something 

 like concentrated essence of fish, due to the secretion of a 

 pair, of large glands situated beneath the skin of the inguinal 

 region, and opening behind the bridge. Freshly caught specimens 

 stink horribly, but when they have become accustomed to being 



