_Sphecodes_ is a genus that has been the subject of prolonged difference of opinion. The species are rather small shining bees, with a red, or red and black, abdomen, almost without pollen-collecting apparatus, and with a short but pointed ligula. These characters led to the belief that the Insects are parasitic, or, as they are sometimes called, cuckoo-bees. But evidence could not be obtained of the fact, and as they were seen to make burrows it was decided that we have in _Sphecodes_ examples of industrial bees extremely ill endowed for their work. Recent observations tend, however, to prove that _Sphecodes_ are to a large extent parasitic at the expense of bees of the genera _Halictus_ and _Andrena_. Breitenbach has taken _S. rubicundus_ out of the brood-cells of _Halictus quadricinctus_; and on one of the few {23}occasions on which this bee has been found in Britain it was in circumstances that left little doubt as to its being a parasite of _Andrena nigroaenea_. Marchal[21] has seen _S. subquadratus_ fight with _Halictus malachurus_, and kill it previous to taking possession of its burrows; and similar observations have been made by Ferton. As the older observations of Smith, Sichel, and Friese leave little doubt that _Sphecodes_ are sometimes industrial bees, it is highly probable that we have in this genus the interesting condition of bees that are sometimes parasitic, at other times not; but so much obscurity still prevails as to the habits of _Sphecodes_ that we should do well to delay accepting the theories that have been already based on this strange state of matters.[22] Friese states that in _Sphecodes_ the first traces of collecting apparatus exist; and, accepting the condition of affairs as being that mentioned above, it is by no means clear whether we have in _Sphecodes_ bees that are abandoning the parasitic habit or commencing it; or, indeed, whether the condition of uncertainty may not be a permanent one. It is difficult to decide as to what forms are species in _Sphecodes_ owing to the great variation. The Hymenopterist Forster considered that 600 specimens submitted to him by Sichel represented no less than 140 species, though Sichel was convinced that nearly the whole of them were one species, _S. gibbus_. It has recently been found that the male sexual organs afford a satisfactory criterion. The position of _Sphecodes_ in classification is doubtful. [Illustration: Fig. 11.—_Sphecodes gibbus_ ♀. Britain.]