428 CLASS vin. 



SERVILLE, Ouvrage accompagne de Planches, Paris, 1843, 8vo (a part 

 of the Suites a BUFFON by RORET). 



As illustrated works : C. STOLL, deaden en Wantsen, Amsterdam, 

 1788, 4to (two parts with Dutch and French text); J. R SCHELLEN- 

 BERG, Cimieum in Helvetice aquis et terris degentium genus, Turici, 

 1800, 8vo (with 14 coloured plates); J. F. WOLFF, Abbildungen der 

 Wanzen, v. Hefte, Erlangen, 1800 1811, 4 to; C. W. HAHN, Die 

 wanzenartige Insecten, getreu nach der Natur abgebildet und be- 

 schrieben, Niirnberg, 1831, and subsequently, since 1836 continued 

 by HERRICH-SCH^JFFER. 



LEON DUFOUR treated of the anatomy of these insects in a 

 monograph, entitled Reclierches anatomiques et physiol. sur les 

 Hemipteres, Paris, 1833, 4to av. 19 pi. 



The Ilemiptera are commonly provided with four wings, of which 

 the anterior are leathery at the base, thick, and not transparent, and 

 at the point membranous (lwmclytra\ or are membranous like the 

 posterior wings, but often stronger and larger than these. The mouth 

 consists of a sucker composed of threads and a case. The case is tubu- 

 lar, grooved above, and consists of joints; it corresponds to the un- 

 der-lip of other insects. The small upper-lip becoming thinner for- 

 wards, covers the base of the sucker. In the groove formed above by 

 the turnover margins of the under-lip, there lie in appearance three 

 setse, but the middle one is double (the two under jaws (maxillae) 

 and the two lateral threads are the upper jaws 1 ). The maxillary 

 palps are entirely absent ; so also are the labial palps, or these last 

 are only in quite a rudimentary state 2 . Thus the beak of the 

 hymenopteTa is constructed for sucking. The fine threads (setcs 

 haustelli, mandibulce, maxilla?) make a wound in the parts of plants 

 or animals, on the fluid or blood of which they feed, the fluid 

 ascending between the threads to the oesophagus above. 



The antennae have commonly only four or five joints, extremely 

 seldom more than eleven. Many species have two or three simple 

 eyes. There are never more, but often fewer, than three joints in 



1 G. R. TREVIRANUS was the first who distinguished the four threads in Cimex 

 rufipes (Annalen der Wetterauischen Gesellschaft, I Bd. i Heft, 1809. s. 171). 

 SAVIGNY has shewn the analogy with the oral organs of other insects, and figured 

 the four filaments in Cimex nigricornis, and in a Nepa, M6m. s. L ani. s. vert. I. 

 1816. PL iv. 



3 SAVIGNY, 1. cit. PI. iv. fig. 30, p. 37. 



