306 The I?ish Naturalist. October, 



of the body, and forms a process rounded at the apex, and containing 

 the eye. In the majority of examples the eye, conforming to the shape 

 of this extension, takes a more or less oval contour. The first antennae, 

 including their terminal setae, generally exceed in length the projection 

 of the eye-bearing process. The distance intervening between the point 

 of insertion of the second antennae and the rim of the eye about equals 

 the length forward thence to the apex of the process. 



In no other characters can I perceive any structural divergence from 

 the type. The variety is plentiful in L. Mask, and apparently supplants 

 the type, though individuals vary somewhat in the development of the 



process (see Plate 41). In L. Corrib, which is only separated by an 



isthmus of three miles broad from L- Mask, I have taken a few examples 



also. 



Holopedium gibberum, Zaddach.— One specimen taken in L. Keel, 



1. of Achill. 



Daphnla hyalina, var. Iacustris, Sars. — L. Corrib. 



Cerlodaphnia pulchella, Sars.— L. Gur, Co. Limerick. 



Bosmina Iongirostris, O. F. Miiller.— L. Gur, Limerick. Corre- 

 sponds to fig. 7, PI. xxxi., Lilljeborg's Clad. Sueciae. 

 Var. cornuta, Jurine.— Three near Rams' I., Lough Neagh. 



Bosmina obtusirostrls, Sars., var. Iacustris.— L. Krne, near 

 Devenish I. L. Neagh, abundant in the northern portion. The 

 specimens here were generally characterised by very long rostra, 

 being from a half to three-fourths the length of the ventral margin 

 of the test. In some these are sharply curved inwards. One, 

 however, with very long straight rostra, had the tips refiexed in the 

 reverse direction. The characters of the specimens generally may 

 be indicated as follows: — 1 B}'es larger than is usual in this species. 



2. The forehead generally with a prominence in front of the eye. 



3. The region of the head not striate as in Lilljeborg's description of 

 the variety. 4 The examples are like figs. 3 and 4, PI. xxxvi., Lillj. 

 Clad. Suec, but with considerably longer rostra. Date of capture, 

 7th November. 



Lathonura recti rostr Is. O. F. MUller. — Bog pools near Creagh, 

 L. Mask ; numerous in pools at Ardee bog. This species, rare in 

 Great Britain, seems very widely distributed in Ireland, especially 

 in shallow marsh pools, with sparse tufts of small species of Carex 

 or aquatic grasses. 



Acantholeberis curvirostris, O. F MUller. — Very abundant in bog 

 pools in Castle Archdale demesne, Fermanagh. 



Lynceus quadrangularls, O. F. Miiller. — I*. Corrib; The Rosses, 

 Sligo. 



L. afflnis, Leydig. — Not rare in L. Mask. 



L. rusticus, Scott. — Bog pools near L. Mask. 



L. costatus, Sars.— L. Mask; L. Gur, Co. Limerick; Glencar, Co. 

 Sligo ; Ardee. 



L. guttatus, Sars.— L. Mask; Glencar, Co Sligo. 



