Scolytidce.'] BHYNCHOPIIORA. 401 



The larvae are white or yellowish-white, fleshy, grubs ami are very 

 closely allied to those of the ordinary Rhynchophora ; in fact they cannot 

 be distinguished from them by any really trustworthy characters (v. 

 Ferris, Larvesdes Coleopteres, p. 412, and Chapuis and Candeze, Cat. des 

 Larves des Coleopteres, p. 228); the only differences are those pointed out 

 by Erichson, who remarks that the head is a little longer and stronger 

 and the mandibles a little longer ; these differences, however, are slight 

 and may of course be accounted for by their habits, on the principle of 

 Xatural Selection ; the integument, moreover, is stouter and more or less 

 shrivelled into rugose folds (etiole) ; the head is of a paler colour ; the 

 body is cylindrical with the posterior extremity obtuse; the thoracic 

 segments are larger and the anal aperture is in the form of an X and 

 bears no appendage serving for locomotion ; in most, if not in all cases, 

 there are no legs ; this character used to be regarded as a distinctive one 

 between the Rhynchophora and the Lamellicornia, Ptinidae and 

 Bostrychida?, but cannot now be regarded as of so much importance, as 

 certain of the Rh t ynchophorous larvae have been found to possess more or 

 less developed legs. 



The larvae of the Scolytidae bear a strong resemblance to one another, 

 and, with the exception of Platypus, which is a little abnormal, they do 

 not require separate notice ; many of them, however, may be recognized 

 by their habits, and especially by the shape and nature of their galleries. 



The following general description of the life history of the Scolytidie 

 has been kindly communicated to me by Mr. W. F. Blandford, who is 

 doing very good work at the group ; and I would here take the oppor- 

 tunity of thanking him very much for many valuable notes regarding the 

 family, which I have embodied in the descriptions that follow: 



" In the fact that the female enters the plant or trunk to lay her eggs 

 the Scolytidfe differ from all other Rhynchophora, by which the eggs are 

 deposited from the outside. 



'' The process of establishing a brood begins in every case by the 

 formation of a vertical entrance-hole through the bark, which in the 

 wood-boring forms is continued deeply into the tree, but which in the 

 bark-feeding species only reaches at most the surface of the Avood. 



" To begin with the latter : The entrance-hole is usually gnawed by 

 the mother ; but some species are polygamous and in these the male 

 performs the operation. He then hollows out a small irregular cavity 

 the brood-chamber and thither certain females betake themselves, and 

 after impregnation commence the ' mother galleries ' at the junction of 

 wood and bast ; in the monogamous species the female is fertilized in 

 the entrance-passage or just outside it 



" From the termination of the entrance-hole the 'mother galleries' 

 run sometimes two in number ; in the polygamous species they form a 

 star-shaped system radiating from the brood-chamber. The eggs are laid 

 alternately on the right and left of the galleries in small excavations 

 from which the larval galleries start. Occasionally they are laid in a 



VOL. v. i> d 



