SINODENDRON CYLINDRICUM, L. 55 



the skin shows several folds to each segment or none. Help 

 can also be got by a close examination of the spiracles, the low 

 power of a microscope being required for certainty. The 

 spiracles are nine in number along each side, viz., on the first 

 segment behind the head and then on segments 4 to ii inclusive. 

 The spiracles are somewhat C-shaped, and their border is 

 brown-red in colour. Attention should be directed to the way 

 in which the C of the spiracles lies, whether the open part is 

 towards the head or facing the hind end. 



The number of joints to the antennae should be observed. 

 There is slight confusion in the literature because some authors 

 do not include a basal joint as part of the antenna, but look 

 upon it as a process from which the antenna springs. In the 

 key which follows I include this so-called process as the lowest 

 joint of the antenna. 



These various characters may be worked into the key thus : — 



A. — Abdominal segments without transverse folds on their 

 upper surface .... Lucaitidce. 



I. — Antennae 5-jointed ; the open side of the C-shaped 

 spiracles faces the head end of the larva. 

 {a) Mandibles and labrum rough — Lucanus. 

 {b) Mandibles and labrum smooth and dimpled — Dorcns. 



II. — Antennae 4-jointed ; the open side of the C spiracle on 

 the first segment after the head is directed towards the 

 hind end of the larva ; in all the other spiracles it is 

 directed towards the head end — Sinodendron. 



B. — The abdominal segments (except the two last segments) 

 have transverse folds on their upper surface; the open 

 side of the C-shaped spiracle of the first segment after 

 the head is directed to the hind end of the larva ; 

 in all the other spiracles it is directed towards the 

 head .... Scarabceidce. 



I. — Last segment of abdomen divided into two by an 



annular groove — Melolontha. 

 II. — Last segment large and undivided; labrum 3-lobed ; 

 claws of feet replaced by a somewhat long plump 

 appendage — Cetonia. 

 III. — Last segment divided but only on the upper surface; 

 labrum not 3-lobed ; feet end in a claw— Gnorinms. 



