LAMELLICOTINIA. 



9 



Mingazzini in his " Ricberclie sul caiiale digerente dei Lamellicorni 

 litofage." * Generally speaking, that of the larva is short and 

 nearly straight, with its anterior part large and encircled by two 

 or three distinct series of glandnlar sacs of varying form. Near 



the posterior end of the intestine there 

 is usually a large dorsal caecum in which 

 part or all of the unassiinilated 

 contents of the stomach are, for a time, 

 retained and which is often visible 

 as a large dark mass through the semi- 

 transparent skin of the last dorsal 

 segment of the body. In many of the 

 CoPBiN^ there is a remarkable dorsal 

 hump apparently serving only for the 

 accommodation of this csecum. The 

 contents form the material with which 

 the cells occupied by the latter insects 

 are repaired when necessary and of 

 which in other groups the cocoon is 

 chiefly or entirely made when the time 

 for pupation arrives. In the Lucanid,!, 

 and probably in some Scakab.eid.e, this 

 sac is little developed and in Passalid.e 

 it is absent. 



In the adult beetle the digestive 

 tube becomes very much elongated 

 and convoluted. The changes which 

 occur in Cetonia and Melolontha were 

 described and figured by Eamdohr in 

 1811 (Abhandlung iiber die Yerdauungswerkzeuge der Insecten). 

 In the adult Passalid the intestine shortly before its termination is 

 completely encased in longitudinal bands of very peculiar large 

 spongy outgrowths which retain their form even in completely 

 dried specimens. 



Larvce. 

 Lamellicorn larvae are exceedingly similar and easily recognised. 

 The body is long, more or less cylindrical and normally bent into 

 the form of the letter C, the legs being well-developed and lying in- 

 side the curve. Although well-formed the legs are only used for 

 locomotion in exceptional cases, as in the Passalid^, the majority 

 of the species l.ving always upon the side or back beneath the 

 ground or in decaying wood, where they are surrounded by suit- 

 able food and need only slight powers of movement. Such 

 movement as is necessary is performed chiefly by contractions 

 of the body rings assisted' by the erect bristles with which these 

 are provided, and some larvas when placed upon a flat surface 

 invariably turn upon their backs in order to propel themselves 

 along in that ^^ay. The head is large, very hard and set at right 



Fig. 5. — Diagrammatic re- 

 pi'esentation of the 

 central nervous sj'stem 

 of a, larva of Passalus 

 (Passalidae); b, imago of 

 the same; c, imago of 

 GoUathus (ScarabiiMcla?). 



* Mitth. Zool. Stat. Neapel, ix. 1889-91. 



