1887.] 357 [Scudder. 



denberg, original drawings of which were shown to the Section ; it 

 is placed by Woodward with it in a distinct genus Leptoblattina, re- 

 markable for the slenderness of the abdomen and the depauperated 

 wings combined with a large prothorax. The two species are readily 

 separable by the form of the prothorax, which is much broader in the 

 English than in the German species. That in each case the animal 

 should have been so completely preserved, and that no wings at 

 all similar to them should have been separately found (unless pos- 

 sibly Gerablattina germari is a case in point), when almost all 

 carboniferous cockroaches are known by their wings alone, is not a 

 little remarkable. There is no doubt that they belong together 

 and should form a distinct genus. The neuration of the two agrees 

 better than was supposed by Woodward. Another species is re- 

 ferred to Lithomylacris and would be interesting as the first instance 

 of the occurrence of the Mylacridae in the Old World if it were 

 correct, but the structure of the mediastinal branches shows without 

 the least doubt that it belongs to the Blattinariae. It is, in fact, 

 apparently a Hermatoblattina, allied to H. lebachensis, but much 

 smaller. 



Mr. Scudder also referred to the glands and extensile organs 

 found on the dorsal surface of the larvae of certain blue butterflies, 

 and which had been shown to excrete a fluid substance attractive to 

 ants. This peculiarity was first observed twenty years ago by 

 Guenee in a European species but had latterly been more fully set 

 forth with illustrative figures by Mr. W. H. Edwards in the case 

 of one of our own species, Cyaniris pseudargiolus. Mr. Edwards 

 showed that there were two sets of organs, a transverse slit on the 

 seventh abdominal segment, through which a minute vesicle could 

 be extruded, and which is the point of attraction to the ants ; and 

 a pair of extensile organs near the spiracles of the succeeding seg- 

 ment, furnished with an apical crown of spicules, the use of which 

 is problematical. 



A recent examination of all the larvae of I/ycaeninae obtainable 

 shows that the transverse slit of the seventh abdominal segment 

 probably exists in all Lycaenidi as well as in some Theclidi, as it 

 occurs among the blues in our own pseudargiolus and comyntas 

 and in the European argiolus, icarus, minima, iolas, egon, admetns 

 and corydon ; and also in Thestor ballus and the European The- 

 clidi, ilicis and roboris. No such gland occurs in our Thecla strigosa, 

 nor in the following European Theclidi : quercus, rubi, spini and 



