112 [ Ma >*. 



SYNOPSIS OF THE BRITISH FORMS OF THE ANDRENA MINUTULA 



GROUP. 



BY R. C. L. PERKINS, D.Sc, M.A., F.E.S. 

 {Continued from p. 75). 



It will never be easy for the Hymenopterist to distinguish the 

 species of these small bees with certainty, unless he makes a special 

 study of fairly extensive material. When the distinctions are 

 thoroughly grasped, they are really not particularly difficult, and the 

 difficulty is due to the variability of all, or nearly all, our species. It 

 is this variability that makes them so difficult to tabulate, even when 

 one can recognise the various forms with certainty and on a very brief 

 inspection. I do not think any useful purpose would be served by 

 giving detailed descriptions of the species, as most of the important 

 characters are shown in the tables already published, but the following 

 notes may be of service. 



A. nana, Kirby (nee Smith, E. Saund.) = schenckella, Perez. 

 Only known to me as British by Kirby's type specimen, but it will no 

 doubt be sooner or later found in numbers. The ? by its shining first 

 and second abdominal segments, the latter very densely and distinctly 

 punctured with the apical margin rugulose, and bearing shallow and 

 rather large scattered punctures, is unmistakeable ; the g has the 

 basal abdominal segment smooth or polished between the punctures, 

 as in alfkenella alone of our British species, but the latter has the 

 apical impressions of the following segments shining and not dull from 

 distinct surface sculpture. 



A. alfkenella, sp. n. (= sp. /3 of my former paper). The <$ 

 resembles the preceding in the character above mentioned and is super- 

 ficially extremely like some examples of minutuloides, but the latter 

 always has the general surface of the 1st and 2nd segments rugulose. 

 It is even more like the continental A. niveata, Friese (which through 

 the kindness of Herr J. D. Alfken I have been able to examine), since 

 that species also has the basal abdominal segments shining, but in 

 niveata the ventral segments are dull and more granulate. A. 

 saundersella <$ has the basal segments rugulose. The ? of alfkenella 

 somewhat resembles that of spreta, Perez, when the latter has become 

 abraded, but the feeble apical impressions of the 2nd and 3rd abdom- 

 inal segments at once separate it. It should be said that the $ of 

 niveata, Friese (nee E. Saund.), has no resemblance to that of alfkenella 

 in spite of the similarity of the J 1 . This bee appears during the first 

 half of July, and I have only taken it on Umbelliferse. It is a coastal 



