Str-piiptera or Stylopidce.'] 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 

 Elenthus ; they are somewhat opaque and membranous and have the 

 anterior margin incrassated ; the abdomen is small and consists of from 

 seven to nine segments ; the legs arc of moderate length, with the coxae 

 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 claw.-. 



Four genera appear to be known, all of which are found in Europe ; 

 Xenos and Stylops also occur in North America ; a 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 

 Xenos is apparently attached to the genus Polities and Stylops to 

 Andrcena, the parasites of these species must probably be referred to new 

 genera. 



Xenos, which inhabits the middle and south of Europe and Xorth 

 America, does not occur in Britain ; it may be distinguished by its five- 

 jointed antennae ; as in Stylopi, 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. Antenna; bifurcate. 



i. Antennae shorter than thorax, six -jointed; tarsi 



four-jointed STTLOPS, Eirby 



ii. Antennae longer than thorax, nye-jointed ; tarsi 

 two- jointed ELEXCHFS, Curtis. 



II. Antennae branched, flabellate, shorter than thorax, 



seven-jointed ; tarsi three-jointed HALICTOPHAGIT?, Ctrlis. 



STYLOPS, Kirby. 



The members of this genus may be known by the formation of the 

 antennae 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- 



