1916.] 211 



In his " Hymenoptera Aculeata of the British Isles," Saunders, in 

 his table of species of Nomada, and also in his descriptions of N. hore- 

 alis and others, but particulai'ly in the case of borealis, appears to 

 have practically considered only what might be called typical examples, 

 even though the variability may be great. Thus the scape of the 

 antennae in (^ ruficornis is in some forms entirely black, while the 

 mesonotum of borealis $ may have distinct red lines. Also the scape 

 of the latter species in the 9 is frequently either red at the base and 

 apex, or entirely red beneath. 



Of ruficornis (quoting vars. fava and signata, as synonyms), he 

 remarks that it is "of extraordinary variability both in colour and 

 size, so that little dependence can be placed on these characters. In 

 his " Synopsis," he says that the varieties are in no wise constant, ex- 

 cepting the var. signata. This remark is not to be taken too literally, 

 since signata itself is distinctly variable in some points, but probably 

 Saunders only meant that he could always distinguish it, or at least 

 its $ , from other forms of ruficornis, while the latter could not be 

 distinguished from one another. As a matter of fact Smith confused 

 a certain variety oiflava* $ with it. This last named author treated 

 the matter very differently from Saunders. In addition to borealis and 

 lateralis Saund. (nee Sm.) the latter of which he caWed bridgmannia7ia. 

 Smith retains signata Jur., and a form he calls lateralis Pz. (which is 

 entirely different from that which Saunders calls laferalis Panz.) as 

 distinct species. As is evident from the note in the " Synopsis," 

 Pt. II, p. 179, under N. bifida, quoted by Saunders, Smith was not 

 satisfied, even after the subti*action of his signata and lateralis, that 

 there were not two species under ruficornis. Probably he was per- 

 plexed by the fact that while some of his " dai-k-coloured varieties" 

 had bifid mandibles, others had not. Smith's series of ruficornis, I 

 may add, contained nearly a score of bifida. Had he removed all 

 these on the mandibular character, he would still have been left with 

 what he calls "dark-coloured vars." (i.e., ruficornis) and "pale ex- 

 amples" (i.e., ruficornis var. fiava). 



Kirby describes N. ruficornis on female examples only. His 

 description of what he considers the type form is more applicable to 

 bifida than to what we call ruficornis, and one would rather infer this 

 to be the case from Smith's MS. note, quoted by Saunders, as referred 

 to above. Smith's collection contains examples with a label " var. y8 

 Kirby." These are specimens of ruficornis. Kirby's vars. y * 8 are, 



' Really the S ■ligna.ta is very difficult to separate from some vavs. of rvfiforais, and also 

 some of jiai'd, and probably many supposed S signata are ■wrongly named. 



