56 



allied f^en era, jolted down some months back for a friend, may prove acceptable to 

 English students: — 



Mycet^a. 



Antennae. With the first joint of the 

 triarticulate club very little wider 

 than the preceding (8lh). 



Labrum. Transverse, truncate. 

 Maxillae. With the two lobes nearly 



equal in length. 

 Max. Palpi. With the apical joint 



elongate-ovate, acuminate. 

 Lab. Palpi. With the second and third 



joints nearly equal in width. 



SVMBIOTES. 



With the first joint of the triarticulate 

 club conspicuously wider than the pre- 

 ceding (8ih), very nearly as wide as the 

 succeeding (lOlh). 



Transverse, slightly emarginate. 



With the inner lobe very short and 

 narrow 



With the apical joint ovate obliquely 

 truncate. 



With the third joint much wider ihau 

 the second (penultimate), globose. 



Mr. Smith exhibited the nest of a species of Larradae, and that of Sphex Lanierii, 

 Guerin, and read the following . — 



Observations on two Species of Fossorial Hymenoptera which construct exterior 



Nests. 



" The varied economy of the fossorial division of the aculeate Hymenoptera, equals, 

 if it does not exceed, that of the Mellifera, The name proposed by Mr. Westwood for 

 the former division, " Insectivora," is by far the most characteristic, since all the fos- 

 sors provision their nests with other insects. As far as my knowledge of the habits 

 of the British species enables me to judge, I believe the majority to be fossorial ; some, 

 however, burrow in wood, whilst others avail themselves of ready-formed burrows, &c., 

 adapted to their purposes, never, as far as I have observed, forming tunnels or recep- 

 tacles for their cells : this appears to be the habit of the species of the Genera Sapyga 

 and Pemphredon. 



" Our knowledge of the economy of Exotic species is very limited ; I have had the 

 pleasure of bringing before the Society some very interesting observations, made by 

 M. Guenzius at Port Natal, upon various species of Hymenoptera, some belonging to 

 the fossorial division. Mr. Bates has also contributed occasional notices of the habits 

 of various species of these insects. In a collection lately received from the latter 

 gentleman, a nest with the insect which constructed it was received, than which nothing 

 could be more at variance with our preconceived ideas of the habits of the genus to 

 which it belongs: the insect is a species of Larrada; the nest is composed apparently 

 as Mr. Bates suggests, of the scrapings of the woolly texture of plants ; it is attached 

 to a leaf, having a close resemblance to a piece of German tinder or a piece of sponge. 

 With the first nest of this description forwarded by Mr. Bates was received a note to 

 the effect that he saw the insect issue from it, and he supposed it to be the builder • a 

 second nest has, however, been received with the information that he had now no doubt 

 of the nest being constructed by the Larrada, as he had observed it repeatedly busy in 

 its construction. I have raised the nest from the leaf, and found four or five pupa- 

 cases of a dark brown, thin, brittle consistency. 



" I am not aware of any similar habit of building an external nest having been pre- 



