CLASS V. INSECTA. 217 



Length of the body 5 — 5^ Uncs, expansion of the wings 10 — 11 Hne-.. 

 Inhabits Germany and England : in the latter it is very rare, and has 

 only been found near Bristol. 



Genus 4'21. LYDA. Fair., SpinoL, Klug., Leach. Pampiiilius. 



Latr., Leach, Edinb. Enct/cl. vol. ix. 141. Cephaleia. Jur'me 



TibiiE, the four posterior furnished on tlie inside with a single spine 



near the middle and a double one beneath. 

 Jmi-vu with no spurious feet. 

 Lydae. Klug. 

 Sp. 1. Lijdu Betulie. 2. Lijda erythrocephala, S^c. 



Genus 422. LOPHYRUS. Lntr., Lcarh. Pteronus. Jurine. IIv- 

 i.OTOMA. Fabr. Tenthredo. Linn., De Gecr, 0/iv., Lam., 

 Panz. 

 AnteniitE pennated in the males; serrated in the females : superior wings 

 with one marginal and three submarginal cells : mandibles tridentate. 

 Sp, 1. Lop//. Pini. 

 inhabits Europe: is very rare in Britain. 



Fam. II. XiPHYDRiAD.t. Leach. 



Abdomen sessile : oviduct composed of two lamelUf, which are serrated : 

 mandibles more or less long, terminated by two strong teeth : uings 

 with the three marginal cells complete : labrum obscure. 



lAirvte with scaly feet, or at least not membranaceous. 



Genus 423. CEPHUS. Latr., Fabr., Panz., Leach. Sirex. Linn. 

 AsTATUs. Klug. Trachelus. Jurine. 

 ^[undibles exserted, longer than wide: neck long: oviduct exserted : 

 antenna; inserted in the front between the eyes, gradually thicker ex- 

 ternally. 

 >^p. 1. Cephus pygmcsus. Latr. 

 Inhabits flowers in fields and hedges. 



Genus 424. XIPIIYDRIA. Latr., Fabr., Panz., Leach. Sires. 



Linn. 

 Mandibles exserted, longer than wide: neck long: oviduct exserted: 



antenna setaceous, inserted above the clypeus. 

 Sp. 1. Xiph. Camelus. 

 Inhabits willow grounds. 



Fam. III. Urocerid.'e. Leach. 

 Abdomen sessile: oviduct filiform, exserted, or inclosed in a groove be- 

 neath the abdomen : mandibles short. 



Genus 425. ORYSSUS. Latr., Fabr., Jurine, Lam., Klug, Panz,, 

 Leach. Sphex. Scopoli. 

 Mandibles with their internal edge not dentated : maxillary/ palpi long 

 and pendulous: antennas filiform, compressed, inserted under the an- 

 terior margin of the clypeus : superior zcings with one marginal cell, 



