44 BEITISH ENTOMOSTRACA. 



(t. IV, f. d), can nearly cover the others, toothed, and, as it 

 were, vandyked round its external edge, and folding np 

 like a fan when the animal does not use it. These organs 

 are generally carried by the animal rolled round under 

 the head, and, as Shaw says, somewhat in the same 

 manner as a butterfly carries its proboscis, their situation 

 being externally visible only by a protuberance. During 

 copulation, however, they become extended in a, straight 

 line, and when so, they nearly equal in length the main 

 part of this curiously -formed organ.* These prehensile 

 inferior antennae are used by the animal to seize hold of 

 and retain the female in copulation, and seem exceedingly 

 well adapted for the pm^pose. In the female (t. IV, f. e) 

 they are differently and much more simply constructed, 

 being merely in the form of two short, stout, and some- 

 what sharp- pointed and flexible horn -like bodies, pro- 

 jecting forwards when the animal is in the water, with 

 a slight curve downwards, and not provided with any of 

 the appendages described above as belonging to the male. 

 The superior antennae, however, are precisely similar to 

 those of the male. 



The eyes (t. IV, f. ¥a) are very large, black, convex, oval- 

 shaped, and composed of an immense nmnber of small 

 lenses, covered with a transparent cuticle. They are 

 situated at the sides of the head, and are fixed upon 

 considerable-sized peduncles, which take their origin 

 from nearly the same part of the head as the antennae, 

 and which are conical-shaped and moveable, the ani- 

 mal having them almost always in quick motion in 

 all directions.! In the centre, between these organs 



* Prevost finds much fault with Shaw's figure of this cui-ious antenna, 

 especially with this proboscis-sha])ed portion of it. VVlieu fully extended, 

 however, as when compressed between two pieces of glass, the figure given 

 by Shaw, though iU proportioned and rouglily executed, is a very fair repre- 

 sentation of it. Jurine's figures, though more elegantly executed, exhibit 

 it such as I have seen it in a very young male only partially extended. 

 Shaw, however, does not figure nor describe the membrane connected with 

 the four appendages, and erroneously represents only three of these in his 

 figure. 



t Burmeister has described the structure of the eye of the Branchipus 



