208 INSECTA, 



FAMILY I. 



SECURIFERA. 



Our first family is distinguished from the following ones by a ses- 

 sile abdomen, or the base of which is joined to the thorax through- 

 out its whole thickness, that seems to be a continuation of it and to 

 have no separate motion *. 



The females are provided with an ovipositior that is most com- 

 monly serrated, and which not only enables them to deposit their 

 eggs, but likewise to prepare a place for their reception. The larvae 

 always have six squamous feet, and frequently others that are mem- 

 branous. 



This family is composed of two tribes. 



In the first, that of the Tenthredinet^, Lat., vulgarly termed 

 3Iouches-a-scie, or Saw-flies, we observe elongated and compressed 

 mandibles ; a trifid or sort of digitated ligula ; an ovipositor formed 

 of two serrated, pointed blades, united and lodged in a groove under 

 the anus. The maxillary palpi are all composed of six joints, and 

 the labials of four ; the latter are always the shortest. The wings 

 are always divided into numerous cells. This tribe forms the genus 



Tenthredo, Lin. 



The cylindrical abdomen of these Insects, which is rounded poste- 

 riorly, composed of nine annuli, and so closely joined to the thorax 

 that the two seem to be continuous, the ragged appearance of their 

 wings, the two little rounded, granular, and usually coloured bodies 

 situated behind the scutellum, together Avith their heavy port, cause 

 them to be easily recognized. The form and composition of the an- 

 tennae vary. Their mandibles are strong and dentatcd. The extre- 

 mity of their maxillae is almost membranous, or less coriaceous than 

 their stem. Their palpi are filiform or nearly setaceous, and consist 

 of six joints. The ligula is straight, rounded, and divided into three 

 doubled portions, the intermediate of which is the narrowest ; its 

 sheath is usually short, and its palpi, shorter than the maxillaries, con- 

 sist of four joints, the last almost bordering on an oval. The abdo- 

 men of the female presents at its inferior extremity a double, mov- 

 able, squamous ovipositor that is serrated, pointed, and lodged be- 

 tween two concave laminae, forming its sheath or case. 



It is by the alternate action of the teeth of this ovipositor, that 

 the Insect makes a number of little holes in the branches, and various 



* The segment, bearing the inferior wings, is separated from the following one or 

 the first of the abdomen, by a transverse incisure or articulation. The other seg- 

 ments then follow uninterruptedly, and without any particular strangulation. 



