([Plate V.] fig. 2 ♂ ♀.)
Gen. Char.: Head transverse, as wide as the thorax, flattish; ocelli placed in a very open curve upon the vertex; face flat, but convex in the centre beneath the insertion of the antennæ; clypeus very slightly convex; labrum transverse, narrowly lunulate; mandibles bidentate; cibarial apparatus moderately long; tongue very acute and fringed with delicate down; paraglossæ barely half the length of the tongue, and acute, their apex fringed laterally with down; labial palpi inserted in a deep sinus, filiform, the basal joint the longest, the rest diminishing both in length and substance; labium about half the length of the entire organ, its inosculation emarginate; maxillæ hastate, rather longer than the tongue; maxillary palpi six-jointed, the basal joint the shortest, the third the longest, the remainder diminishing gradually in length, and all declining in substance from the basal joint. Thorax oval, rather pubescent; prothorax transverse, curving to the mesothorax, whose bosses are inconspicuous; scutellum transverso-quadrate; post-scutellum transverse linear; metathorax truncated. Wings with two submarginal cells, and a third commenced, the second about as long as the first, and receiving both the recurrent nervures, the first near its commencement, and the second nearer its extremity; legs robust, with the posterior tibiæ and plantæ densely clothed externally with short hair; the plantæ broad; the second joint of the tarsus inserted at the lower angle of the plantæ; claws bifid. Abdomen subtriangular, truncated at its base, not longer than the thorax.
The MALE differs in having the antennæ as long as the thorax and curved; the posterior coxæ very large and robust, the trochanters small and triangular; the femora large and much swollen in the centre, the posterior tibiæ very large and triangular and convex externally, and the plantæ longer than the rest of the tarsus, and slightly curved beneath longitudinally.
NATIVE SPECIES.
1. labiata, Panzer, ♂ ♀. 4-4½ lines.
([Plate V.] fig. 2 ♂ ♀.)
GENERAL OBSERVATIONS.
The name of this genus comes from μακρὸς, long, and ὦψ, face, in allusion to the length of that portion of the head, although this assumed discriminative characteristic is scarcely suitable; this again constitutes another of the many instances wherein it would have been much preferable to have imposed a name without any significancy than one which is not thoroughly applicable. It is, indeed, always dangerous to attach a name to a new genus which has reference to some individual peculiarity, for it may eventually exhibit itself as limited to the one single species or sex to which it was originally applied, as to every other subsequently discovered species in the genus it may be inappropriate.
Nothing, so far as I am aware, is known of the habits of these singular insects, which, I believe, have been caught only three times in this country and then only the male sex.
The first, which is in the collection of the British Museum, was brought by Dr. Leach from Devonshire; the second was caught in the New Forest by the late John Walton, Esq., distinguished for his knowledge of the British Curculionidæ, and who kindly presented it to me for my collection when I was at the zenith of my enthusiasm for the Hymenoptera, and with that collection it passed to Mr. Thomas Desvignes, in whose possession it remains; and the third was caught by Mr. Stevens, at Weybridge, in Surrey. Why I enter so particularly into these circumstances is, that the genus is extremely peculiar both for scientific position and for structure. In the latter the male is extremely like the male of Saropoda and its female is more like the female Scopulipedes among the Apidæ than one of the Andrenidæ, especially in the form of the abdomen and of the intermediate and posterior legs, as well as in the length of the claws and the low insertion of the posterior joints of the tarsi upon their plantæ, a peculiarity not occurring in another genus of the Andrenidæ.