The insects of this family may be easily known by their perfectly 

 sessile abdomens, by their peculiar oviduct formed of 2 serrated 

 lamella, and by their ample wings of many cells. Many of them 

 fejo-n death when alarmed and bend down their heads and antennae 

 solbrcibly as to show the membrane that connects the thorax. 



The larvae of this family bear a strong resemblance to those of 

 the Lepidoptera, but they have more abdominal or false feet, they 

 feed upon the leaves of plants, are very sensitive, and have a peculiar 

 manner of rolling themseves up, when touched, like a convoluted 



shell. 



The present genus was separated from Nematus by Dr. Leach in 

 the 3rd vol. of the Zool. Misc. in a paper upon the external cha- 

 racters of the Tenthredinidae : the hinder legs, dilated in both sexes, 

 indicate a different mode of life from the other Nemati and are pro- 

 bably useful in flight. 



When the first edition of this work was published, only one spe- 

 cies of Croesus was known, but in the 1st vol. of the " Annales de 

 la Soc. Ent. de France" M. Foulgues de Villaret has described 3 

 new species, 2 of which are supposed by Mr. Stephens to be British. 



1. septentrionalis. Linn. Curt. Brit. Ent. pi. 17. ?. 



This was formerly considered a rare insect, being taken occa- 

 sionally at Darent-wood Kent, in Norfolk, near Lyndhurst, &c. in 

 June, but it now sometimes appears in abundance. Mr. C. Parsons 

 observed the larvae near Southend feeding on the hazel ; they agreed 

 with the figure in our plate copied from the Ent. Mag., but did not 

 change to flies till July. Mr. C. J. Paget found the larvae on willows 

 in a meadow near Great Yarmouth the end of August ; they were 

 small but "in such numbers," he says in his letter, "that some trees 

 are perfectly bare: I never observed a more extensive blight : there 

 are literally thousands in this meadow alone." I took a female at 

 Bungay in Suffolk several years since. 



2. varus? Be Vill. Ann. Soc. Ent. Fr. 1. 306. ;;/. 11./. 8. 3. 



Palpi and clypeus white : abdomen black, middle of the 2nd segment and the 

 following to the 7th ferruginous: 4 anterior legs pale ferruginous, hinder 

 thighs ferruginous tipped with black : wings unclouded : expanse 9 lines. 

 Beginning of June, Birch-wood. Ste. 



3. laticrus De Fill. v. I. j}. 307. pl.n.f.7. ? . 



Palpi reddish, 3rd, 4th, 5th and 6th segments of abdomen ferruginous: legs 

 black, tips of anterior thighs ferruginous, anterior tibiae and tarsi reddish 

 white, intermediate pitchy, base of the former whitish : superior wings with a 

 fuscous cloud : expanse one inch. 

 Said to have been taken near London. 



I think it very probable that Mr. Stephens's specimens are merely 

 varieties of the male and female of C. septe7itrionalis. 



The Plant is Crepis tectonm, Smooth Hawk's-beard. 



