DTXASTIN^. 259 



legs are alike in the two sexes, and in some the whole aspect is 

 identical. There is a slight difference, however, which is almost 

 invariable throughout the subfamilj and serves to determine the 

 sex when more obvious distinctions are wanting or doubtful. The 

 last ventral segment is more or less angular at the extremity in 

 the female, the angle coinciding with the apex of the last dorsal 

 segment or pygldium : while in the male this segment is excised at 

 the apex, leaving an interval between it and the apex of the 

 pygidium filled by a membrane. The pygidiuni itself is often 

 extended and iuturned in correspondence with this conformation 

 in the male. 



Habits and Metamorphoses. 



The Dtkastin^ being practically confined to the warm regions 

 of the earth and almost all of singularly retiring habits, our 

 knowledge of their metamorphoses and modes of life is as yet 

 exceedingly scanty. With the exception of the flower-haunting 

 Cyclocephalini of Tropical America, they appear to be practically 

 all nocturnal or crepuscular, lying hidden by day beneath the 

 ground or in dark recesses. For this reason, combined with the 

 sombre and inconspicuous colouring which is the usual accompani- 

 ment of such a mode of life, they are not easily found, although 

 generally abundant, and in very few cases have their early stages 

 been traced. The only genus in which anything approaching 

 complete information is available is Orijctes (the Ehinoceros 

 beetles), of which not only are the species exceedingly abundant, 

 but one of them (Oryctes yiasicornis, which reaches the north- 

 western part of the Indian region) is one of the largest of the 

 insects inhabiting European countries. This beetle has been the 

 subject of valuable anatomical I'esearches, some of which have been 

 already referred to. 



An interesting fact observed in different genera of Dynastin^, 

 and in different parts of the world, is the considerable growth 

 which takes place in the egg between the times of deposition and 

 hatching. Like those of other Lamellicornia, the eggs are 

 spherical, whitish and moderately smooth. 



The larvae, as far as they are known, do not differ in any marked 

 degree from those of the Cetoniin.^ and allied subfamilies. They 

 are rather stout-bodied, clothed with stiff erect hairs, the head not 

 very large, without eyes, the mandibles strong, the maxillae single- 

 lobed, and the legs well and equally developed, but not long. Like 

 the Cetoniiis"^ also, they feed during this stage upon decaying 

 vegetable matter, and sometimes upon living roots or woody 

 tissues. The food of the adult beetles is uncertain, but it probably 

 consists chiefly of sweet or resinous vegetable exudations. 



An account recently published of the habits of a species found 

 in the Southern States of North America is interesting as showing 

 that in this group, as in the Geoieupin.e, Copein.e and other 



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