LAND AND FRESH WATER MOLLCSCA OF BUTE. 171 



HeliridsB in as far as it relates to the species 

 observed in Bute, and thus bring together all the 

 information we at present possess concerning the 

 niunber of species known to occur in the island, 

 and also what we know as to their distribution. 



By way of explaining how I am in a position to 

 attempt this work, it may be stated that in October, 

 1886, the Fishery Board for Scotland requested me 

 to proceed to Rothesay to carrj' out some investiga- 

 tions at the Royal Aquarium ; and I was stationed 

 there till the end of June in the following year, 

 that is, between eight and nine months. During 

 these months a good deal of my leisure time was 

 devoted to the examination of the land and fresh- 

 water invei'tebrate fauna of the island. 



My modus operandi was somewhat as follows. 

 During the shorter days the locality in the vicinity 

 of the Atiuarium was examined, and here a few 

 interesting " finds '' were secured, including the rare 

 Lhnax (Anidlid) gagates. One or two visits were 

 also m.-ule to Loch Ascog and Loch Fad, but com- 

 paratively little was done throughout the winter. 

 As soon, however, as the longer days of spring and 

 early nummev arrived, I frequently visited, in the 

 early morning and also in the evening, localities 

 more distant than those I had been able to reach 

 during the winter months. Two or three times 

 every week, when the weather was favourable, I 

 was in the habit of leaving Rothesay between 3 and 

 4 a.m., or sometimes earlier, and proceeding to some 

 place ]n"eviously fixed on, where I would spend a 

 short time collecting material and taking notes, 

 after which I returned so as to reach the Aquarium 

 before 9 a.m. In this way I have visited Loch 

 Ascog, Loch Fad, Greenan Loch, Ettrick Bay, St. 

 Ninian's Bay, Kames Bay, and other places. A good 

 deal of time was thus also devoted to the exami- 

 nation of the shores as well as the landward part of 

 the island, and that without interfering in any way 

 with the Board's work. These early morning 



