MODE OF DETERMINING SPECIES. 09 



feeding caterpillars. It is a wliitish grub, thick towards the 

 shoulder and tapering to the head and tail. The segments are 

 very distinctly marked, and the last segment is armed with two 

 hook-like appendages curving upwards. When it is about to 

 change to the pupal form, it descends the trunk of the tree, 

 and hides itself in the moist earth about the roots ; and after it 

 has obtained its perfect form, it is generally to be found in the 

 crevices of the bark. 



On Woodcut X. Fig. 5, is shown another of these Beetles, 

 Meligethes ceneus. This genus is known by the squared and 

 metallic body, the long elytra, and the tliird joint of the 

 antennffi, exactly as long as the fourth and fifth together. The 

 form of the maxilla is shown gpn the same illustration at 

 Fig. b. All the Beetles of this genus are very small, and are 

 invariably to be found in flowers, creeping from their hiding 

 places under the petals when the flower is gathered or shaken. 

 Being very minute insects, a careful examination with a some- 

 what powerful lens is needed to distinguish the species, and, 

 even then, the little creatures are so like each other in size 

 and colour, tliat the entomologist is obliged to abandon the 

 usual mode '>f detcrm.ining species, and to trust to the bumber 

 of notches in the tibiae of the first pair of legs. 



This species is variable in colour, being blue-black, violet, 

 or dark green-blue, over which is a SDrt of brassy gloss. It 

 seldom exceeds the twelfth of an inch in length, and is a very 

 good example of its genus. It is plentiful throughout Eng- 

 land. 



Still keeping to the same family, we take another of the 

 sub-families, the Ipsina, which have the front of the head 

 lengthened and covering the labrum, the foiu'tli joint of the 

 tarsus being very minute. Our first example of these insects is 

 Rhizophagus ferrugineus, which is shown on Woodcut XL 

 Fig. 1. These Beetles have much narrower bodies than the 

 preceding, the antennae are short and boldly clubbed, with 

 a large basal joint. The head is not sunk in the thorax, 

 and the elytra are not so long as the abdomen. They are 

 mostly to be found under the bark of trees, but some are 

 fond of inhabiting old bones, and are even parasitic in ants' 



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