1890.] 



SCO PARI A ATOMALIS. 

 BY EUSTACE E. BANKES, M.A., F.E.S. 



Owing to the kindness of my friend Mr. Samuel T. Ellison, of 

 Perth, I have just had the long-wished-for chance of examining a 

 most interesting series of this so-called species from various localities 

 in Perthshire, and have been able at last to form a definite opinion on 

 the vexed question as to the true relations between S. amhiguaJis and 

 8. atomalis. The series contained some very small dark extreme forma 

 of the latter, and these were connected by every possible shade of 

 variety, with larger and lighter sj^ecimens, which were identical with 

 small southern amhigualis : some were so exactly intermediate between 

 the two extremes, both in colour, size, and markings, that it was quite 

 impossible to say to which species (?) they should be referred. These 

 intermediate lin]cs seem to prove conclusively that atovialis is, as has 

 for some time past seemed probable, merely the small dai'k highland 

 form of the well-known amhirjualis ; and a cai'eful examination failed 

 to reveal any genuine characters by which any portion of the series 

 could be separated from the rest. The extremes, it is true, when com- 

 pared together ivithout the connecting links, may look distinct, but the 

 gap between them is not nearly so wide as between the extremes of 

 such very variable species as S. niercurella and S. dubitalis. 



In order to enable me more fully to investigate the matter, Mr. 

 Philip B. Mason has kindly lent me tracings of highly magnified 

 drawings of the anal appendages, with their constituent parts, of all 

 the Scoparicd ; the differences shown between the appendages of 

 iS. amhigualis and atomalis are very slight, and would be easily ac- 

 counted for, if, as was probably the case, the drawings had been made 

 from dried specimens. 



There can then, I think, be no longer any doubt that S. atomalis 

 must for the future lose its specific rank, and the name be retained 

 for the small dark highland variety of S. amhigualis. 



Seeing that conspicualis and gracilalis have now been merged 

 into ulmella and alpina respectively, while Zelleri, scotica, ingratella, 

 portlandica, and atomalis have been degraded from specific rank into 

 their proper places as varieties, and joZfceoZeMca has disappeared alto- 

 gether from our list, the genus Scoparia, as represented in Britain, 

 seems at length to have been reduced to its natural limits. The only 

 possible species about which there can still be any question is S. 

 hasistrigalis, which some think may prove to be identical with S. am- 

 higualis ; I regret to say that I am not sufficiently well acquainted 



