DAPHNELLA. 109 



with several strong setae, and the whole organ presents a 

 curved appearance. In full-grown females (t. XII, f. 3) 

 the ovary contains upwards of twenty young, and the ani- 

 mals then present a different appearance from those which 

 have no ova (t. XIII, f. 1). The young resemble the 

 parent from their birth. Twenty-four hours after being 

 born they appear as represented in t. XII, f. 4. 



The motion of the Sida through the water is a sort of 

 rapid running movement. They are generally inactive, 

 and adhere in a peculiar manner by the back of their head 

 to the side of the vessel in which they are contained, 

 remaining there for hours. They adhere most probably 

 in the same way to the weeds in the water where they 

 are found, as it is by skimming the stems of the weeds 

 that they are detached and caught. They do not appear 

 to be numerous in the localities in which I have found 

 them, and indeed are of rare occurrence. 



Hab, Back fishpond at Overstone Park, Northamp- 

 tonshire, July and August, 1849 ; ditch near Richmond, 

 opposite Isleworth, August, 1849 ; found near Dublin, 

 by Professor Allman, VV. Thompson, Esq., July 1848. 



Genus 2 DAPHNELLA. 



Inferior antennae very large ; both branches consisting 

 each of only two articulations. 



1. DAPHNELLA WINGII. Tab. XIV, figs. 1-4. 



Carapace elongated, rounded at the back, slightly curved 

 at inferior extremity, and having a small mucronation, 

 somewhat truncated in front, and of a beautiful, clear, 

 crystalline transparency. 



The head is long and narrow. 



Eye (t. XIV, f. 4 c] large, round, composed of upwards 

 of forty crystallines, and nearly filling the upper part of 

 the head. 



