3i6 



CONCHOLOGICAL NOTES FROM THE ARGENTINE 

 AND URUGUAY. 



W LIONEL E. ADAMS, B.A. 



(Read before the Society, September gth, igoS). 



The results of a month's collecting in the neighbourhood of Monte- 

 video, and another month's exploring at several places along the 

 Parana from San Nicolas to Colastine, about three hundred miles 

 up the river from Buenos Aires, may interest English collectors. 



At Montevideo the River Plate is sixty-four miles wide, and con- 

 siderably salt, species of Mytilus, Mactra^ and Trochus being found 

 on what is practically the sea-shore. The country is perfectly flat 

 for fifty miles round, with the exception of the " Cerro," a conical- 

 shaped hill, nearly five hundred feet high, from which the name 

 Montevideo is said to be derived. Where the land is uncultivated, 

 it is very exasperating to wander on account of all sorts of cactus, 

 and one has to be careful not to sit down for miles together, for 

 where there is a spot clear of cactus, there are sure to be ants. 

 Moreover, the shell collector finds absolutely no land species except 

 Helix aspersa and Helix lactea, which are European importations. 

 These are sold in the ^lontevideo markets at about sixpence a pint. 

 However, there is a muddy little river — the Miguelete — flowing into 

 the harbour, which I visited several times after a flood, and secured 

 a good set oi AinpuUaria cVorbignyana Phil., Anodonta rotunda Spix, 

 and two species of Plaiwrbis. 



In places this river overflows into swamps, one of which was very 

 prolific in Pliysa {Aplecia) aurantia Carpenter, some of which I kept 

 alive for some days to watch. They exhibit the same curious irrita- 

 bility so characteristic of our fontinalis, jerking their bodies sideways 

 violently when coming in contact with each other. They are likewise 

 thread-spinners. The mantle completely conceals the shell, overlap- 

 ping along the back. 



After discharging at Montevideo, we proceeded up the Parana to 

 load for the homeward passage at several places between Arguerich 

 and Colastine. The Parana is not a single stream with a well-defined 

 centre current, but a mass of water thirty to sixty miles wide, mean- 

 dering through a maze of wooded islands aud scrub-covered swamps, 

 with stretches of open water ten miles wide here and there. Beyond 

 the swamps, the country extends along a dead level to the Andes on 

 the west and to the hills of Uruguay on the east. Now and then 

 tlie river-bank rises to the height of a hundred feet, and upon these 



