THE ENTOMOLOGIST. 101 



upon as a clew, for in individuals which must be admitted to 

 be of the same species, size takes a wider extent of difference 

 than in almost any of the genera of bees. St. Fargeau, who 

 maintains the parasitism of the genus, accounts for it by 

 saying that in depositing their eggs in the nests of the 

 Andrena3, Halicti, and Dasypoda, the Sphekodes resorts to 

 the burrows of the species of these genera, indifferent to 

 their adaptation to its own size ; and thus, from the abundance 

 or paucity of food so furnished to its larvae, does it become a 

 large or a small individual. Westwood says they are parasitic 

 upon Halictus. Latreille says they are parasites. They are 

 certainly just as destitute of the pollinigerous apparatus as 

 the preceding genus. Mr. Thwaites once thought he had 

 detected a good specific character in the differing lengths of 

 the joints of the antennae, but I believe he never thoroughly 

 satisfied himself of its being practically available. At all 

 events, great difficulty still attaches to their rigid and satisfac- 

 tory determination. There is an array of entomologists who 

 deny their being parasites. IVIr. Kirby says they form their 

 burrows in bare sections of sand-banks, exposed to the sun, 

 and nine or ten inches deep, and which they smooth with 

 their tongues. But then, in impeachment of the accuracy of 

 his observation, he further supposes there are three sexes, 

 founding his statement upon what Reaumur remarks of 

 having observed pupae of three different sizes in the burrows. 

 In the first place, it is not conclusive that these pupae were 

 those of Sphekodes; and secondly, we know that this condition 

 of three sexes is found only in the social tribes, wherein the 

 peculiarity of the economy exacts a division of offices. 

 Therefore his adoption of this inaccuracy militates against 

 the reception of his other statement. But Smith also states 

 that they are not parasites, and apparently founds his assertion 

 upon direct observation. It still, however, remains a debatable 

 point, from the fact of the destitution of the pollinigerous 

 brushes, and thence the character of the food necessary to 

 be stored for the larvae. It would be very satislaclory if 

 these apparent inconsistencies could be lucidly explained. 

 If, however, it be ultimately proved that Sphekodes is a 

 constructive bee, as well as Prosopis, we have still this fact 

 exliibited by our native genera, that none of the sub-family 

 of shorl-tonged bees or Andrenidac are parasitical. This is a 



