FEET OF THE DYTICUS. 57 



The first pair of legs, however, are tlie most interesting. 

 We have already seen that, in very many Beetles, tlie tarsi of 

 the front pair of legs are dilated in the male, bu^ there are 

 none which even approach those of the Dyticus in complexity 

 of structure. The geodepliagous males have the under surface 

 of these dilated joints merely fnrnislied with a pad, but the 

 Dyticus has a most wonderful array of suckers, exactly analo- 

 gous in principle to those which stud tlie arms of the cuttle- 

 lish. One of these legs is shown on Woodcut No. VI, Fif;:. c. 

 The three basal joints of the tarsus are enormoiisly swollen, so 

 that they assume a plate-like shape. Their upper siu"face is 

 smooth enough, but the under surface is covered with suckei"s, 

 one of them very large, and the second about half its size, and 

 a multitude of smaller suckers. The larger suckers are placed 

 directly upon the joint, and the others are at the end of 

 slender footstalks, looking something like the ' patera ' cham- 

 pagne glasses with the stems much attenuated. 



In order to see this beautiful structure properly, several 

 specimens ovight to be used. One can be simply cleaned, aiid 

 viewed as an opaque object, while another is cut so as to give 

 a section of the joints, and to show the manner in which the 

 suckers spring from them. Three more specimens should also 

 be prepared, but mounted as transparent objects in Canada 

 balsam. This will be found rather a difficult process, but one 

 which will very well repay all the trouble. The difficulty is 

 to get rid of the air which remains in the suckers, and which 

 makes the mouth of each sucker look like a black shining- ball. 

 A structure, similar in principle, though varying in detail, is 

 found throughout this group of Beetles. 



The female is, as has been stated, very different from the 

 male in appearance. She does not possess the wide tarsi which 

 are so conspicuous in her mate. The elytra are very different 

 from those of the male, and, instead of being smooth and 

 polished, are deeply grooved nearly as far as the middle. 



The voracity of this Beetle is really astonishing. It will eat 

 almost any kind of insect, or any kind of meat, raw or cooked, 

 preferring the former. Sometimes it is placed in fresh-water 

 aquaria by those who are not acquainted witli its powers, 

 and the result is always disastrous. Not only will it attack 

 every living creature in the aquarium, but during the night, it 



