236 



[March, 



Fig. 1. 5. stellatus. 



The character alluded to has reference to the point of origin of the lower branch 



of the upper section of the superior 

 cubitus. In S. stellatus this nervure arises 

 either from the same point as the transverse 

 nervule closing the cellula thyridii, or from 

 the transverse nervule itself immediately 

 leloiv its beginning. In S. latipennis, on 

 the other hand, the same nervure arises 

 considerably below the beginning of the 

 transverse nervule. 



My friend Mr. King has kindly ex- 

 amined his materials in these species, and 

 finds the character in the main to hold 

 good. It rests with other entomologists 

 to decide whether it is of local or general 

 importance. The point is confessedly 

 slight, hardly to be called a character ; 



Fig. 2. S. latipennis. 



yet, should its general occurrence be proved, it may be used with caution as an aid 

 to identification. 



I may add that all the <j? of S. latipennis possessed by me are comparatively 

 small ; and further, that I have never taken this species at any of our larger streams. 

 — Kenneth J. Morton, Carluke, N. B. : January 24th, 1889. 



[The character alluded to by Mr. Morton may be put in other words. In S. 

 stellatus he means to say that apical sector No. 7 arises directly (or nearly so) from 

 the commencement of the transverse nervule closing the cellula thyridii, so that 

 apical cellule No. 6 is acute (or nearly so) at the base. In S. latipennis sector No. 7 

 arises somewhat below the commencement of the transverse nervule, closing the 

 cellula thyridii, so that cellule No. 6 is distinctly truncate at its base. The best charac- 

 ter whereby to separate the two lies in the form of the superior appendages of the $ ; 

 but, unfortunately, these are very frequently retracted in drying, and no longer 

 visible. 



I have compared Mr. Morton's character with my own materials. Of 21 ex- 

 amples of both species in my British collection, the result is that they remain as 

 originally placed, only one specimen remaining slightly doubtful. Upon turning to 

 my general European collection, I find 35 examples from very varied localities. The 

 small neural character holds good as a rule, but there are certain examples (placed 

 as latipennis), chiefly from Austria and Switzerland, in which it seems to fail. A 

 slight suspicion has long existed that there may be a third species, and on my re- 

 examination I was struck by certain characters (perhaps ilhxsory) in the superior 

 appendages of the individuals placed as latipennis (alluded to above) which merit 

 investigation from fresh specimens. Mr. Morton's neural character is useful, but it 

 is so slight that it would be contra leges Naturae to expect it to be practically con- 

 stant. — B>. McLachlan]. 



Aquatic habits of Salda. — -While collecting Saldai in September last on the 

 mud-flats of Lelant Harbour, West Cornwall, I was curious to know how they 



