136 COLEOPTERA 



There is but one genus, and for a long time only two or three 

 species were known, and were great rarities in collections ; in 

 the last few years the number has been raised to nearly forty.-' 

 They are remarkable beetles with oblong form, and a somewhat 

 metallic upper surface, wliich is much sculptured, and possesses 

 four yellow, smooth spots on the elytra. According to Mr. George 

 Lewis they are found feeding at the running sap of trees, but the 

 larvae are not known. Helotidae are peculiar to the Indo-Malayan 

 region (including Japan) with one species in Eastern Africa. 



Fam. 35. Thorictidae. — 2\irsi five-jointed, none of the joints 

 broad; front coxae small, rather proviinent, but not at all trans- 

 verse ; five visihle ventral plates, all mobile ; metasternum very 

 short ; antennae short, ivith a solid club. This little family, con- 

 sisting of the genus Thorictus, appears to be a distinct one, 

 though the stru.cture has only been very imperfectly studied. It 

 is peculiar to the Mediterranean region, where the species live in 

 ants' nests. They appear to be on terms of great intimacy with 

 the ants ; a favourite position of the beetle is on the scape of the 

 antenna of an ant ; here it hooks itself on firmly, and is carried 

 about by the ant. Like so many other ants'-nest beetles, 

 Thorictidae possess tufts of golden hair, which secrete some 

 substance, the flavour of which is appreciated by the ants ; these 

 tufts in Thorictidae are situated either at the hind angles of the 

 pronotum, or on the under surface of the body on each side of the 

 breast ; Wasmann thinks that when the beetles are riding about, 



as above described, the ants have tlien 

 an opportimity of getting at the patches 

 on the under surface. 



Fam. 36. Erotylidae. — Tarsi five- 

 jointed, but tviih the fourth usually very 

 smcdl, the first three more or less broad 

 and pubescent beneath. A ntcnnae strongly 



, , . „ ,, clubbed. Front and middle coxed acetcc- 



' hula round, vjithout ajigular prolongation 



Fig. Ill .—Tritoma hiimstidata. externally ; five visible ventral segments. 

 Erotylidae. Britain. A, Larva This is now a large and important family 



(after Perns) ; B, perfect Insect. r, ^ 1 -1 r^ n n ■ -, 



ot about 1800 species, but it is chiefly 

 exotic and tropical, its members haunting the fungoid growths 



' Ritsema, Catalogue of Helota, Notes Leyden Mus. xiii. 1891, p. 22-3, and xv. 

 1893, p. 160. 



