THE KNTOMOLOGIST. 251 



Croraaglilan Mountain (pronounced Cromagloun) is worth 

 a day to ilseli : the tunnel on the load to the upper lake is 

 the best ])oint from wliicli to commence the ascent : on a 

 shoulder of the mountain, at an elevation of about 1000 feet, 

 is Loch Criujcaun, the only known habitat of Limuiea invo- 

 lutus; the shell is found attached to stones and rocks at 

 some depth below the surface of the water, and tasks the col- 

 lector's patience and ingenuity to secure it uninjured, being so 

 fragile as to break with the slightest pressure. It is closely 

 allied, but in different points of structure, to Limnaea Bur- 

 nettii and L. glutinosus : L. Burnettii has only been observed 

 in Loch Skene, in Dumfriesshire, and resembles L. involutus 

 in having the spire depressed so as to form a concavity ; but 

 its shell is larger and stronger, and the mantle of the animal 

 does not envelop the shell entirely, as is the case both in 

 involutus and glutinosus. In L. glutinosus the spire is not 

 depressed as in L. involutus, but forms a slight projection, 

 and the mantle covers the entire shell, which is as fragile as 

 that of L. involutus, but slightly larger. L. glutinosus occurs 

 in Lake Bald and other mountain tarns in North VV'ales, but 

 does not appear to be so exclusively an alpine species as L. 

 involutus or L. Burnetii. It seems probable that involutus 

 is the representative of one or other of these species, the 

 remnant of a colony v\hich may have reached Killarney in 

 glacial times, dwarfed by unfavourable climatal conditions, 

 but still holding out in its mountain fastness. 



1 have elsewhere drawn attention to the northern character 

 of the insect fauna of the South of Ireland : excluding in- 

 serts of universal occurrence, the number of species of Lepi- 

 doptera which are common to the North of Scotland and the 

 South of Ireland is very striking. 1 may mention, in illus- 

 tration of this, the following Lepidoptera found in Kerry and 

 Perthshire, and mostly common in both places, of which the 

 majority are unknown in Southern England : — Ccenonympha 

 'i}phon, Sesia scoliaiformis, Bombyx Callunte, Acron}cta 

 Myiicaj, Hadena rectilinea, U. contigua, Calocampa exoleta, 

 C. vetusta, Acidalia fumata, Dasydia obluscata. And when 

 the insect does occur in all three divisions of the United 

 Kingdom, and has a northern variety, as in the case of 

 C Davus (Typhon), Bombyx Quercus (Callunae), it is the 

 Scotch and not the English form which occurs in the South 



