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Notes on Pontobde/la muricata. 



By 

 The Hon. Henry Gibbs. 



A PontoMella lived in my tanks for about six months of the present 

 year. I first placed it in a wide shallow tank with a variety of Actinice 

 and a few Hermit Crabs, but no fish of any sort. When first intro- 

 duced the leech was very restless, and wandered all over the tank. 

 After a day or so, however, he took up his abode on the glass, close 

 to the surface. He remained in this spot about three months, and if 

 disturbed would always go back to it. He never noticed any of the 

 other animals, and did not appear in the least sensitive to the stinging 

 power of the tentacles of the Actiniai. I have frequently seen him 

 plunge his head and neck in amongst the tentacles of a large Anthea 

 cereals who lived near him, and he treated T. crassicornis with a like 

 disrespect. 



So soon as the weather grew warm, the leech displayed signs of 

 uneasiness, and finally left his place on the glass, and retired to a cool 

 corner formed by the slate back and side of the tank, close to the 

 syphons of the aerating apparatus, where he remained two months and 

 a half 



He never appeared to notice sticks or nets moving near him in the 

 water, but would remain in his usual position, viz., the base fixed to the 

 wall of the tank, the body sticking out horizontally for about half its 

 length, and the fore part doubled under, so that the mouth was pressed 

 against the under side. 



If, however, I placed my hand near him in the water he always 

 displayed excitement; he would raise his head and most of his body 

 completely out of the water and wave himself in the air, or more 

 frequently he would feel about with his head in the water, going over 

 the rocks and sand at the bottom of the tank, as if searching for food. 

 He never detached his base on these occasions, and always drew sharply 

 back if he touched my hand, so that he did not intend to bite me, as I 

 at first suspected. 



