56 C.-M. EF. von HAYEK 
the antennae of the male are a little longer and the segments slightly more transverse 
than those of the female. 
DISTRIBUTION. The largest number of species occur in the New World and 
in the Oriental region and the fewest in Africa. Neboiss (1956) lists a large number 
of Australian Lacon species but all those known to me (approximately half Neboiss’s 
total) with the exception of modestus (Boisduval) belong to Agrypnus as defined 
in this work. JL. modestus (Boisduval) appears to be widespread, though not 
common, in the tropics. As far as is known all the other species are comparatively 
limited in their distribution. 
BIOLOGY AND HABITS. Very little is known of the biology and habits of the 
members of this genus. 
The adults of the European species are generally found under the bark or 
in the decaying stumps of coniferous trees. Adults of modestus (Boisduval) 
(Fleutiaux, 1947 : 275) and of certain American species (Kirk, 1922) have been 
found under the bark and in wood-borer galleries in the timber of deciduous trees. 
The larvae have been found in the same places. Those of L. marmoratus (Fabricius) 
are known to feed on Bostrychid larvae (Kirk, 1922) and it seems probable that 
the larvae of other species are also predaceous on wood-boring larvae. 
SPECIES INCLUDED IN THE GENUS 
The following 106 species known to me are congeneric with the type-species 
Elater atomarius Fabricius (=Lacon punctatus (Herbst)). 
Lacon altaicus (Candéze) comb. rev. 
Adeloceva altaica Candéze, 1881 : 2. 
Lacon altaicus (Candéze) Fleutiaux, 1926 : 93. 
Adelocera altaica Candéze; Tscherepanov, 1957 : 187. 
The description is based on an unrecorded number of specimens from Altai 
standing as lepidoptera in the Gebler collection. I have not seen this material, 
which may be in the MNHN, Paris; ZI, Leningrad (Horn, 1935 : 87); or IRSNB, 
Brussels (Fleutiaux, 1945 : 81). 
The generic attribution is based on the description. 
Lacon antennatus (Lewis) 
Adelocera antennata Lewis, 1894 : 27. 
Lacon antennatus (Lewis) Fleutiaux, 1926 : 93. 
Holotype. JAPAN: 9, Sap. [on underside of card mount = Sapporo]; Adelocera 
antennata Lewis, type [Lewis]; Japan. G. Lewis 1910.320 (BMNH). 
Lacon argentatus (Candéze) comb. n. 
Opatelus argentatus Candéze, 1874 : 42. 
LECTOTYPE (present designation). Brazit: ? 9, Bates coll. Ega; Janson 
coll. 1903.130; Opatelus argentatus mihi [sic] n. sp. [Janson] Candéze [Gahan] 
