TNTRODFCTTON. 3 



upon (Iccayinii trce-stumji.s or K)jj;s, they aiv strikiiiifly (liHcrciit 

 fiuni them in this rcspiMt and in the absence of tliat extreme 

 variability of size within tiie s])ecies so characteristic of the 

 LuCANlDyE. 



Like the Copri.N-*;, dealt with in a ])revious vohnne, both 

 groups may be re<^arded as on the whole beneticial to mankind. 

 None are recorded as injurious to any serious extent, and, as 

 the result of their combined activities, i^reat f|uantities of 

 dead tree-stumps and logs are disintegrated and removed, 

 which would otherwise remain to hinder the growth of fresh 

 vegetation. It can perhajDs scarcely be counted as a further 

 merit that certain native races attribute ])eculiar virtue to 

 the strange-looking male beetles. I have been infonued by 

 Dr. Hamid Khan that in Southern India certain liill-tribes 

 use the mandit)les meflicinally, and of a certain Chinese species, 

 Calcodes nitiduf<, the form of the male mandibles is unknown, 

 every specimen brought to Em-ope having had them removed, 

 probably for a similar reason. 



Larv.«. 



As already stated, the larvae of the two families differ very 

 considerably, those of the Passalid^ being adaj)ted to a more 

 active existence than those of the Lucanidve, which, like 

 Lamellicorn larvae in general, have very little power of move- 

 ment from place to place. The Lucanid larva differs little 

 from other "" wliite worms," as Lamellicorn grubs are called 

 in various parts of the world. The body is curved into the 

 shape of the letter C and normally lies u])on its side, the three 

 pairs of legs brought close together and useless for locomotion, 

 although well (levelo])ed. The surface of the body is rather 

 smooth, the segments l)eing without transverse fokls and with 

 little or no covering of hairs oi- spines. The 4 or 5 segments 

 forming the ])ostcrior half of the body are large and the anal 

 opening, which in otiier Lamellicornia lies in the same ])lane 

 as the mandibles and other organs of the mouth (generally 

 described as transverse), is here at right angles to that plane 

 (generally described as longitudinal). This serves to dis- 

 tinguish at a glance any larva belonging to the family, at 

 least so far as they are at present kno%vn. The ventral 

 surface of the last segment, as in other Lamellicornia, has on 

 each side a patch of very short close-set sjiines, forming what 

 is sometimes called the raster ; the exact arrangement of 

 these spines differs in different s])ecies. The s])ines ])robably 

 serve to assist the mandibles in holding food-matter or 

 perhaps in cleaning the delicate organs of the mouth. 



The legs consist of a coxa, trochanter and two other joints, 

 terminating in a single claw. All the legs are of nearly ecpial 

 length, but those of the third pair have an extension of the 



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