( Ixxvii ) 



group of Plebeiids, and this makes me regard them as a sort of 

 datum from which to note the divergences of other groups, 

 without really any sort of idea that they are basal or phylo- 

 genetically older. Their dorsal armature is definitely bilateral, 

 each side is rather narrow and pointed, and has an angulated 

 hook hinged to it. Perhaps more characteristic is the large 

 somewhat spindle-shaped clasp, with a comparatively small 

 toothed margin at its extremity. This toothed margin is 

 cur-led round and difficult to observe unless pains be taken to 

 straighten it out, or see it from a proper angle. These clasps 

 are wonderfully similar throughout the group, and it is 

 the toothed ends to which one looks for the easiest means 

 of distinguishing them. 



" Another group is that of the Lycaenopsids {Celastrina 

 argiolus), in which the dorsal armature, still bilaterally 

 distinct, is rather flattened, and any points it may have are 

 pai'ts of it, the special character of the group being that the 

 hinged hooks are wanting. The clasps vary much throughout 

 the group. 



" Another group is that of the Everids with dorsal arma- 

 ture, which we may regai-d as that of the Plebeiids with the 

 two side portions united in the middle line. 



" In the Lycaenid {Lycaena avion) group we have the clasp 

 of peculiar form, very little varied through a number of rather 

 dissimilar species. 



" In Tarucus theojjhrastits and Lampides hoeticus we have 

 examples of which I will only say they do not belong to any 

 of the above groups, and may be taken as samples of the large 

 field unrepresented in Britain. 



' ' The slides now shown illustrate the appendages of all our 

 British and one or two other Plebeiids. Those of Argios, L. 

 (ciegon) and argyrognomon I have already exhibited. Argus 

 is well distinguished from argyrognomon, and all British 

 species by the large development of the serrations into strong 

 teeth. Orhitulus has the serrated end remarkably rounded, 

 almost disk-shaped. Astrarche has a specialisation on the 

 clasps, of which some trace also exists in its near relation 

 eiomedon, and is quite an exception to the remarkably feature- 

 less character of the shaft of the clasp in the group. There is 



