CHYDORUS. 125 



Intestine convoluted (t. XVII, f. A), having one incom- 

 plete convolution and half another. Lower part of the body 

 of the animal has a lobe springing out from its edge like 

 a spur. Setae at the joint of the abdomen finely plumose, 

 and jointed at about half their length. 



Abdomen very broad, lamellar, densely and strongly 

 serrated on lower edge; sinuated deeply on anterior 

 margin, and terminating in two stout claws and two 

 small ones. 



The mandibles are strong, rounded towards the ex- 

 tremity, which is armed with sharp teeth. The first pair 

 of feet consists of a strong fleshy sort of body, ciliated on 

 the upper edge, and terminating in five long and strong 

 filaments, which generally project outside of the shell. 

 The other feet consist of broad plates, with the branchial 

 apparatus attached, and resemble a good deal those of 

 the Daplmia. 



The motion of this insect is peculiar ; it generally lives 

 at the bottom of the vessel in which it is kept, and when 

 disturbed, it bounds up by rapid short motions in a curved 

 sort of line, and then returns in the same manner to the 

 place from where it rose. It is very heavy and slothful 

 compared with the other genera, and I have frequently 

 tinned it over two or three times before it has moved. 



Hob. Not uncommon in ponds and ditches, during 

 the summer months. Near Isleworth, and elsewhere in 

 the neighbourhood of London. In Yetholm Loch ; and 

 pool on Bowmont Water, near Yetholm, Roxburghshire. 



Genus 2 CHYDORUS. 



LYNCEUS, Miiller, et auctorum. 

 CHYDOKUS, Leach, Supp. Encyc. Brit. 



Baird, Ann. Mag. Nat. Hist., ii ; Trans. Berw. Nat. Club, ii. 



Character. Nearly spherical in shape. Beak very 

 long and sharp, curved downwards almost into the shape 

 of a crescent. Inferior antennae very short. 



