IO8 A NEW ZEALAND NATURALIST'S CALENDAR. 



creeping certain little Crustacea* about half an inch long 

 resembling long wood-lice or slaters. Now it takes an 

 enthusiast to appreciate and wax eloquent on the beauties 

 of a wood-louse, and yet these creatures have been a source 

 of great interest to many besides myself. I wonder if it is 

 possible to communicate this interest to others. It must 

 be more than twenty years since Captain Hutton first 

 drew my attention to the occurrence of these animals at 

 Tomahawk Lagoon. I at once made an expedition to 

 the spot, collected a number, and was delighted to find 

 that they belonged to a genus of marine forms (Idotea), 

 which was not previously known to have any fresh-water 

 representatives. Idoteas are familiar enough in our 

 harbour, and are often to be met with in abundance along 

 the sea wall at the cement works. They are usually of 

 a greenish colour, are an inch or two in length, and, owing 

 to their numerous feet, have a "creepy" look that is very 

 trying to some people's nerves. Some two or three years 

 after the description of Idotea lacustris was published, 

 Dr Coppinger, a surgeon on board of one of her Majesty's 

 ships, collected a species of Idotea at Port Henry in the 

 Straits of Magellan, and on examining his specimens at the 

 British Museum it was found that they were identical with 

 our Tomahawk species. More recently still, Dr Chilton 

 met with the same creature at the mouth of the little 

 stream which runs into Sawyers' Bay, and, following up 

 the stream, he found that it was quite at home in the fresh 

 water. This led him to follow up the little stream to 

 its source, away up on Mihiwaka, and there, at an elevation 

 of 1500 feet, our little Idotea was still to be found. One 

 discovery leads on to another, and I was induced to search 

 in other directions. So, furnishing my boys with tubes 

 and a specimen for identification I got them on one of 

 their excursions to search the streams on Flagstaff and 

 Swampy Hill, and sure enough, from a height of 2000 feet, 

 they brought me down my little friend. It is not a 

 very common thing to find marine forms invading fresh 



* Idotea lacustris. 



