THE LUCAXIDJE. 323 



There is more uniformity in the form of the larvae and the nature of the metamorphosis in the 

 Lamellicorns than in almost any other tribe of Coleoptera, A Lamellicorn larva may be known by 

 its fleshy cylindrical form, curved inwardly towards the hind extremity. The curvature appears not to be 

 under the will of the insect, except, perhaps, in its very earliest stage, and consequently the obese grub 

 habitually rests on its side. Its skin is of fine, semi-transparent texture. Its head is- rounded and 

 horny, and furnished with strong mandibles, but destitute (with rare exceptions) of eyes. The thoracic 

 segments bear three pairs of horny feet, and the ninth or terminal segment of the abdomen is greatly 

 enlarged, and generally divided into two parts by a transverse furrow, simulating a division into two 

 segments. The food of these larvae varies according to the different sub-families, those belonging to 

 the Coprophagous divisions living, like the adult insects, on the dung of animals, and the others 

 generally on vegetable substances, living or decayed. The former pass through their various stages of 

 growth rapidly, but the larva? of the vegetable-feeding species are slow in reaching the pupa state. 

 The slow-growing species, especially the Cockchafers, the life-histoiy of many of which has been 

 well investigated, take from two to three years. The mode of passing the pupa period of their lives is, 

 similar in all. The grub, namely, on completing its growth, forms in the soil an oval chamber, in 

 which it undergoes the change. There are some exceptions to this rule, the most remarkable of 

 which are certain cases in which species are parasitic on other members of the tribe. 



The Lamellicornia include some of the largest and handsomest Beetles known ; the sub-family 

 Cetoniinae, or Rosechafers, uniting elegance of form and beauty of colour in a remarkable degree. 

 The horns, with which their head and thorax are often armed, and which imitate in shape in different 

 species those of the Rhinoceros, the Goat, the Stag, the Reindeer, and other large animals, and their 

 general herbivorous habits, have induced some authors to consider them as the analogues of the 

 Pachyderm and Ruminant orders among the Mammals. Notwithstanding their bulk, they are, as a 

 rule, strong flyers. The Cockchafers are well known for their capabilities in this respect ; as is also 

 the Geotrupes, " the shard-borne Beetle, with his drowsy hum " of Shakspere. Trichius fasciatus, a 

 handsome species, sometimes found abundantly in South Wales, flies about flowers with the activity 

 of a Humble Bee, which it much resembles. Even the great Rhinoceros and Elephant-beetles of' 

 tropical America, weighted by their horny armature, fly long distances over rivers and lakes in sultry 

 evenings. To sustain thess efforts of prolonged flight, strong wing-muscles are necessary, and a well- 

 developed respiratory apparatus ; we find accordingly that the ordinary breathing tubes in these 

 insects are not only greatly enlarged and ramified, but furnished throughout the body with supple- 

 mentary air-vesicles, which act in the double capacity of lightening the specific gravity of the body 

 and intensifying the aeration of the nutritive fluid, on which increased muscular volume and 

 energy depend. 



More than 7,000 species of this highly-endowed tribe have been already described, and numbers 

 of new species are continuallv being discovered by travellers. They are divided into two families, 

 very unequal in point of numbers, viz., the Lucanidae, or Stag-beetles, and the true Lamellicornia, or 

 Scarabaeida?. 



FAMILY LUCANID.E. 



This family is distinguished from the Scarabaeidae by the leaflets of the antennal club being fixed.- 

 This character is so constant that, added to the widely different general form of the insects, and the 

 largely-developed projecting mandibles of the males of the majority of the species, it has induced many 

 modern authors to consider the Lucanidae as an independent group, totally distinct from the true 

 Lamellicorns. If we look only at the extreme or more specialised forms of the two families, no other 

 conclusion could well be arrived at ; and it happens here, as in other large groups of Coleoptera, that 

 the more specialised forms constitute the great majority of the genera and species of both families. 

 On comparing, however, the less typical genera of the two, such as the JZsalince in the Lucanidae, and 

 some of the flat Trcxjince in the Scarabaeidae, an approximation is observed between the two groups. 

 If we trace the gradation of forms upward from this common point, we find, on the one hand, the 

 Lucanidae increasing in development of mandibles, with crown of head and thorax losing all traces 

 of armature ; while on the other hand, in the Scarabceidce, the mandibles dwindle to useless, partly- 

 membranous blades, and the horn-like processes on the head and thorax increase in size and variety 

 of form. 



