RECLASSIFICATION OF SUBFAMILY AGRYPNINAE 87 
DANOSOMA Thomson gen. rev. 
Danosoma Thomson, 1859 : 103. Type-species: Elater conspersus Gyllenhal, by monotypy. 
Delox Quelle, 1932 : 208 [as a subgenus of Adelocerva sensu auct., nec Latreille]. Type-species: 
Elater conspersa Gyllenhal, by subsequent designation (Arnett, 1955 : 607). 
GENERIC DIAGNOSIS. Tarsal claws without a group of setae at the base (Text-fig. 12). 
Tibial spurs absent (Text-fig. 10). Mesepisternum does not from part of the margin of the 
mesocoxal cavity; mesepimeron forms part of margin of mesocoxal cavity (Text-fig. 3). Second 
antennal segment moniliform, third weakly triangular, each almost equal in length to the fourth 
and following segments. Antennal grooves long, extending almost the entire length of the 
prosternopleural suture and deep enough to accommodate the antennae. Body clothed with 
narrow scales. Prothorax simple, without constriction behind the anterior angles; lateral 
carina present. Propleurae and metasternum without well-defined grooves for the accommoda- 
tion of the tarsi of the anterior and middle legs. Scutellum simple, without carina. Tarsi 
simple, without ventral lobes (Text-fig. 15). 
RANGE OF VARIATION FOUND WITHIN THE GENUS. The four species included 
in the genus bear a close resemblance to one another and also to certain Lacon 
species from which they are easily distinguished by the absence of setae at the base 
of the claws. The curious similarities between certain palaearctic and holarctic 
species are discussed in the section on the distribution of the species. 
HisTORY OF THE GENUS. Thomson established Danosoma for a single species, 
conspersa Gyllenhal, in which the antennal grooves are long enough to accommodate 
the antennae and the base of the prothorax is narrower than the base of the elytra. 
In addition the posterior angles of the prothorax are bicarinate and not turned 
outward at the apex. Seidlitz (1888 : 169) reduced Danosoma to a subgenus of 
Adelocera (sensu auct. nec Latreille = Lacon Castelnau of the present work). 
The subgenus was not generally accepted and Arnett (1953 : 7) treated Danosoma 
as a subjective synonym of Lacon Castelnau. 
Quelle was aware of the existence of Danosoma but nevertheless established 
Delox as a subgenus of Adelocera (sensu auctt., nec Latreille) for four species, 
including conspersa Gyllenhal, which lacked setae at the base of the claws. 
Arnett (1955 : 607) designated conspersa as the type-species of Delox, thereby 
making Danosoma and Delox isogenotypic. 
I consider the absence of the setae at the base of the claws to be of sufficient 
importance to warrant the establishment of a genus. The genus Danosoma is 
here redefined on this basis. 
SEXUAL DIMORPHISM. The species included in this genus do not appear to 
display any marked sexual dimorphism. 
DistrisuTion. Northern Palaearctic and northern Holarctic regions. Two 
species occur in each region. There is a close resemblance, both in general 
appearance and in the shape of the aedeagus, between the palaearctic conspersa 
and the holarctic brevicornis and the palaearctic fasciata and the holarctic obtectus. 
Quelle (1932: 209) drew attention to the similarities between conspersa and 
brevicornis and fasciata and his interpretation of profusa. Quelle misinterpreted 
profusa, believing that the posterior angles of the prothorax were simple, whereas 
