HYMENOPTERA. 583 



otlicrs, l)nt \vbich are mcmljranoas. This family is composed of two tribes, [the Tenthredineia and 

 Urocerafa]. 



The Tentiiredinet.e — , 

 Or Saw-flies [as they are commonly called, from their saw-like ovipositor], have the mandibles long and 

 compressed, the lower lip divided into three lobes, the ovipositor composed of two plates, toothed like 

 a saw, united, and lodged in a channel beneath the anus ; the maxillary palpi are always composed of 

 si\ joints, and the labial of four; the wings are always divided into numerous cells. This trilje is 

 composed of the genus 



Texthredo, Linn. 

 The abdomen is cylindric, rounded lichind, 9-joiiitcd ; the form of the antennre varies ; the mandibles 

 are strong and toothed ; the mamillary palpi arc filiform and G-jointed ; the lower lip is divided at the apex 

 into three lobes ; the labial pal]ii arc only 4-jointcd. It is wiih the alternate motion of the saws of the 

 ovipositor that these insects make a succession of small boles in the branches or other parts of trees, 

 in each of which an egg and a drop of frothy liquid are discharged, the latter of wdiich has the effect of 

 closing the hole. The wound thus made becomes more and more convex by the increase in size of the 

 egg, and sometimes these parts assume the form of a gall, either woody or pulpy, according to the parts 

 injured; these tumours form the abode of the larvai which reside within them, and the insect makes 

 with its teeth a circular hole for its escape. But in general these larvte are external feeders, devouring 

 the leaves. They greatly resemble the Caterpillars of Lepidopterous insects, but have from eighteen 

 to twenty-two feet, or only six, which distinguishes them from caterpillars, which have from ten to 

 tixtcen feet. Many of these false caterpillars roll themselves into a spire, and others have the 

 cxti-enhty of the body elevated in the air. In order to undergo their change, they spin, either on the 

 earth or on the plants upon which they have fed, a cocoon, in which they remain unchanged for many 

 months, changing to pupce only a few days before they become perfect Sawflies. 



Some, in many of wliich the antennae are not more than nine-jointeit, with two spurs at the tip of the fore tibia?, 

 have the ovipositor not exserted, the labrinn apparent, the inside of the four hind tibiii; without spices in the 

 middle, or with oidy one ; the larvte have from twelve to sixteen false le^s. 



Cimbex, Oliv. (Crabro, Geoffr.), comprises those species which have the antenna; 

 abkc in both sexes, and terminated by a knob or a reversed cone rounded at the 

 tip, preceded by four or five joints, and the two subcostal ner\'es are conti{i;uous 

 without a wide intermediate space. The larvje have 22 feet ; some when disturbed 

 discharg-e from pores of the body, often to the distance of a foot, drops of a 

 g-reenish liquid. Dr. Leach has divided this g;enus into numerous others [adopted 

 by EnE;lish authors], founded upon the number of joints in the antennse preceding 

 the club, their relative sizes, and the arrani^ement of the cells of the wing-s. 

 Perqa, Leach, (one of these genera), peculiar to New Holland, diflers from the 

 rest by having; the four posterior tibiae furnished with a moveable spine in the middle, the posterior angles of the 

 scnteUum produced into short obtuse teeth, the antenna very short and 6-jninted. 



,Si/zi/(jonia, King, has also 6-jointed antenna?, and the radial cell is appendieulated. The species are Brazilian, 

 as well as those of Fac/ii/lo^sHcta, K\ng, v^hicli have antennae composed of five joints, and the fore-wings dilated 

 near the apex. 



Saint Fargean, in his work on the T en t lire dint dcv, adopts only the genus Perga, and we also consider the genera 

 of Leach as simple divisions in the genus CimbeXy the type of which is the Tenlliredo fcmorata, [a large and rare 

 Iti-itish species]. 



llyloioma, Latr. {Cnjphis, Jur.), has the antenna apparently only 3-jointed, the third forming a long prismatic 

 or cylindric mass ; the greater number have a spine on the inside of the four hind tarsi, in the middle. The larva? 

 have from eio-hteen to twenty feet. Type, Tentliredo Rosa, Linn., [a common British species]. 

 Schizocenis, Latr. {Cn/ptus, Leach), has four submarginal cells, and the male antennas forked. 

 Ptll/a, St. Farg., differs from Hylotoma in having only three submarginal cells. Sometimes the antennre have 

 at least nine joints, and do not terminate in a mass. 



Tenthredo proper, have nine simple joints in both sexes; the larva? have from IS to 22 feet. The number of teeth 

 in the mandibles varies in the perfect insect from two to four ; the wings also vary in the number of the cells, and 

 brnce various subgenera have been established, such as AHanfus, Dalerus, Ncmaius, Jur., and Pristip/iora ax\d 

 some others of Leach, [such as Selandrki, Feuusa, Dosyt/u-us, Emphytus and Crcesus]. Type, T. Scrophular'uc, 

 Liun., a common species, much resembling a AVasp, the larva of which feeds on the Water Betony. De Geer has 

 described a singular species, which in the larva state infests the leaves of our fruit trees under the form of a small 

 bUek sluc^ and to which he refers the Tenthredo Cerasi, Linn. ; this larva is black, and covered with a slimy 

 serrpuon. Peck, an American naturalist, has given the complete history of another species, which has a 

 similar larva. 



(T^ 



