188/.] ON OllNITHORHYNCHUS PARADOXUS. 3G3 



not only superficially, but anatomically, from its nearest relative 

 in Britain, A. hortensis, Fer., has, until a few months ago, always 

 been confounded with it, and has consequently not been recorded as 

 British. It differs specially from all others of the genus in being 

 keeled on the back in the young state, and is easily known from 

 A. hortensis, of which I have specimens taken in company with 

 A. bourijuiynati, by its perfectly white foot-sole and its narrow 

 side-bands. 



A. bour-ffuignati appears to be very well distributed in Britain: up 

 to the present it has been found in Yorkshire, Middlesex, Hamp- 

 shire, Sussex, Cornwall, and my brother has recently taken a speci- 

 men at Conistou, Lanes. It has also been received from the neigh- 

 bourhood of Clonmel, in Ireland. 



Hyalina draparnaldi. Beck. — This species in Britain has 

 appeared to be confined to the western parts (Cornwall, Devon, and 

 Wales), and has not been found further east than Bristol. The 

 occurrence therefore of a colony of the species at Isleworth is very 

 remarkable, unless on the supposition that they were accidentally 

 introduced from elsewhere with plants, as they were found close to 

 a garden. The specimens are remarkable as belonging to a variety 

 which may be called maculosa, characterized by having whitish 

 spots irregularly placed all over the surface of the shell. This 

 condition has been recorded by Pascal in the allied species H. 

 cellaria, Miill., and is important because it is apparently an inter- 

 mediate form between the translucent horny shells of this and the 

 opaque calcareous ones of other species, the spots being due apparently 

 to little deposits of carbonate of lime. 



The Secretary read the following extract from a letter addressed to 

 him by Mr. Albert A. C. Le Souef, C.M.Z.S., dated Melbourne, 

 11th March, 1887:— 



" Tou will be interested to know that I have now a pond for living 

 Duckbills {Ornithorhynchus paradoxus) in our gardens. The pond 

 is about fifty feet in diameter, and is lined with rough stone ; it has 

 a small island covered with ferns and rushes in the centre. In it 

 are artificial burrows, and also boxes with dry grass in them. 

 Water is always flowing through the pond. The Duckbills seem to 

 do very well in it, and are a great attraction. I shall make further 

 experiments in keeping them, with a view, if possible, of sending you 

 some of them by my son Dudley, who, I think, will again visit 

 England about the end of this year." 



The following papers were read :- 



