Entomological Society, 



6471 



in determining, within a few hours of first meeting with this insect, the genus to which 

 it pertained, The analytical method pursued by Dr. Redtenbacher, in his admirable 

 work above cited, and the clearness and precision of his generic characters, affording 

 peculiar facilities to the student ; but having advanced thus far, safe progress was inter- 

 dicted, for, although Dr. Redtenbacher's description of S. latus satisfactorily applied, in 

 most respects, to the insect before the Meeting, two, apparently important, discrepancies 

 presented themselves, namely, that of his S. latus the author distinctly says that the 

 thorax has " the upper surface smooth, shining, not. punctured" and " the interstices 

 between the striae of the elytra not punctured" whereas, in all the individuals of the 

 insect under consideration, the prothorax is conspicuously, although minutely and 

 sparsely, punctured, and the insterstices of the elytral striae present numerous irregularly 

 disposed punctures, very evident throughout the basal moiety, but obsolete on the apical 

 half. Under these circumstances, he had considered it right to defer bringing the 

 insect before the Society until he had ascertained its legitimate appellation, for which 

 purpose he had intended to transmit specimens to Vienna on the first opportunity 

 which should present itself. In the meanwhile, however, Dr. Gerstaecker's valuable 

 * Monographic der Familie Endomychidae,' Berlin, 1858, came to hand, in which the 

 genus Symbiotes is treated, and the species fully described, and at once all doubt as to 

 the identity of our insect and S. latus, Redt., was dispelled. As the present insect so 

 closely resembles in its facies the common Myceta?a hirta, Marsh., Steph., that it may 

 be very pardonably confounded with it (its usually larger size and more parallel elytra 

 might perhaps betray it), the following comparison of the characters of the two nearly 

 allied genera, jotted down some months back for a friend, may prove acceptable to 

 English students : — 



Mycetjea. 



Antennae. With the first joint of the 

 Particulate club very little wider 

 than the preceding (8th). 



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. 



Symbiotes. 



With the first joint of the triarticulate 

 club conspicuously wider than the pre- 

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

 succeeding (10th). 



Transverse, slightly emarginate. 



With the inner lobe very short and 

 narrow 



With the apical joint ovate obliquely 

 truncate. 



With the third joint much wider than 

 the second (penultimate), globose. 



Mr. Smith exhibited the nest of a species of Larrads, 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 Relieve the majority to be fossorial ; some, 



