124 Mr. J. O. Westwood’s Memoirs 
1 think, enable us satisfactorily to determine the family to which 
the perfect insect is referable. 
In the month of November, 1826, this gentleman discovered 
near Hornsey, Middlesex, several of. these larvee alive and buried 
in the solid part of a branch of willow, which was perforated and 
devoured in different directions in a manner similar to the opera- 
tions of the goat moth (Cossus ligniperda). Pl. X. fig. 1, repre- 
sents the larva in one of the burrows. It would appear that 
Linnzus was aware that the larvee of his Strex Camelus (which is 
also a species of the genus Xiphydria) feed upon wood ;* although 
De Geer, (Hist. d, Ins. vol. i. p. 567,) being ignorant of the 
economy of Urocervs gigas, placed that insect, together with 
U. juvencus and spectrum, with the [chneumonide, and supposed 
its larvee had similar habits to those of that family ;+ as did also 
Geoffroy, who established the genus Urocerus several years before 
Linnzeus published the twelfth edition of the ‘“* Systema Nature,” 
wherein he called the same insects by the generic name of S?rex, 
which Jatter name must consequently be rejected. 
Modern Entomologists however do not appear to be acquainted 
with the economy of the insect under description, for M. Le 
Pelletier de Saint Fargeau, in his Monograph on the Tenthre- 
dinide, tells us (Preface, p. 13) that he is neither acquainted 
himself with the larve of this genus nor of Xyela of Dalman, nor 
does he believe that they were at all known. Dr. Leach formed 
this genus and Cephus into his family Xiphydriade, and amongst 
its characters we find the following: ‘“ Larvee with scaly feet, or 
at least not membranaceous.”{ This description I shall however 
prove will not at all apply to the larva of Xiphydria. Latreille, 
in his * Genera Crustaceorum, &c.,” makes no mention of the 
larvee of these two genera; but in the ‘‘ Régne Animal”§ he 
forms of them a primary division of the Tenthredinide, and says, 
“ Les larves vivent probablement dans J’intérieur des vegetaux 
ou dans les vieux bois ;” and in a late work he observes, without 
any expression of doubt, “ Larves sans pattes membraneuses vivent 
dans l’intérieur des vegetaux.” || Dr. Klug, in his Monograph 
on the German Siricide, in which the present group is included 
* « Habitat in ligno antiquo corrupto.”—Faun. Suec. No. 1576. 
+ ‘ Jene connois point leurs vers, ni le lieu ou ils vivent, mais la longue tarriére 
de la femelle fait assez connoitre qu’ils doivent €tre obligés de pondre leurs ceufs 
dans d’autres corps, a la maniére des Ichneumons.” 
¢ Samouelle’s Compend. p. 267. 
§ Reégne Animal, vol. iii. p. 459. 
|| Familles Naturelles, p. 442. 
