Strepsiptera or Stylopide.] ABNORMAL COLEOPTERA. 455 
with the sutures of the dorsal pieces all distinct ; the portion behind 
these pieces or postscutellum is more or less conical and prolonged con- 
siderably over the base of the abdomen; the wings are very large and 
fan-shaped with a few diverging nervures which are almost wanting in 
Llenchus ; they are somewhat opaque and membranous and have the 
anterior margin inerassated ; the abdomen is small and consists of from 
seven to nine segments ; the legs are of moderate length, with the cox 
of the two anterior pairs somewhat elongated ; the femora are simple ; 
there are no tibial spurs; and the tarsi have the underside of the joints 
strongly lobed beneath and are not furnished with terminal claws. 
Four genera appear to be known, all of which are found in HKurope ; 
Xenos and Stylops also occur in North America 3 & species of the 
former genus has also been found in a Brazilian species of Sphex ; 
Elenchus is represented in Mauritius, and a Stylopised bee has 
been observed in Tasmania; our knowledge of the group, however, 
is exceedingly limited, and many more species and genera will probably 
be discovered ; in North America Stylopised individuals of Odynerus 
quadricornis and of a large species of Sphex have been observed, and as 
Aenos is apparently attached to the genus Polistes and Stylops to 
Andrena, the parasites of these species must probably be referred to new 
genera, 
Xenos, which inhabits the middle and south of Europe and North 
America, does not occur in Britain ; it may be distinguished by its five- 
jointed antenne ; as in Stylops, the tarsi are four-jointed, but the last 
Joint is entire, whereas in Stylops it is deeply emarginate ; the wings, 
moreover, in the latter genus, are much less rounded ; the three genera 
found in Britain may be distinguished as follows : it must be remembered 
that the characteristics apply to the males only, 
I. Antenne bifurcate, 
i, Antenne shorter than thorax, six-jointed; tarsi 
ETTISA CET Sp a ete dlcelia laidiaaal Srytops, Kirby 
ii. Antenne longer than thorax, five-jointed; tarsi 
Egonfemitcdee see SPR ire Bai On! ELENcHUS, Curtis. 
II. Antenne branched, flabellate, shorter than thorax, 
seven-jointed; tarsithree-jointed . . . . . , . Haticrornagus, Curtis. 
STYLOPS, Kirby. 
The members of this genus may be known by the formation of the 
antennz which most closely resemble those of Xenos but are six-jointed ; 
the basal joint is somewhat cup-shaped, the second very short and trans- 
verse, and the third is produced on its internal side into a dilated hollow 
lobe extending beyond the fifth joint ; the fourth, fifth and sixth are com- 
paratively long, the fourth being the longest ; the eyes are very promi- 
nent ; the rudimentary elytra are not clavate ; the wings are very large 
and have the sides straighter than in the other genera and produced in 
front into a round blunt angle ; the nervures are very fine but distinct ; 
the post-scutellum is elongate and rounded at apex ; the posterior tro- 
