1389. i !75 



anal plate scarcely horny, but large, shining, with its front straight, but laterally 

 and posteriorly semicircular, ending in a slight point in the middle of its hind- 

 margin. 



" Mines the leaves of Helianthemum guttatum, Cerastium vulgatum, Plantago 

 lanceolata, in April, and probably feeds on a variety of plants growing on sandy 

 soils. One of the ends of its galleries is fixed to the under-side of a leaf, and from 

 this the larva eats its way into the leaf, leaving the gallery fixed outside, as certain 

 Coleophora larvse do. If driven back, or even merely frightened, it retreats into 

 its gallery, and will not venture out again. Never found in a mine after sunrise ; 

 the mine occupies an elongated oval space between two ribs of the leaf. 



" Pupa in a small silk cocoon, covered with grains of sand." 



13, Cheyne Eow, Chelsea, S.W. : 

 October 15th, 1888. 



ON THE INTERPRETATION OF NEURAL STRUCTURE. 

 BY E. MEYRICK, B.A., F.E.S. 



An esteemed but inexperienced friend of mine once discovered 

 that in a certain New Zealand butterfly vein 11 of the fore-wings 

 sometimes ran into 12, and sometimes did not. In recording the fact 

 in a scientific periodical, he ventured to draw the inference that neu- 

 ration ought never to be employed to define genera. Of this guileless 

 person I was at once reminded in reading Lord Walsingham's interest- 

 ing statistics of variation in Cerostoma, and the unwarranted conclusion 

 which he draws from them. 



The variability of veins 7 and 8 (called by Lord Walsingham the 

 apical veins, though, as a matter of fact, neither is apical) in the fore- 

 wings of Cerostoma has long been known, and is expressly alleged by 

 von Heinemann as a reason for not sub-dividing the genus ; of this 

 Lord Walsingham's figures supply an interesting and satisfactory 

 confirmation. They prove that von Heinemann was right, and literally 

 nothing more. Variability in Cerostoma no more entitles us to expect 

 variability in (Ecophora, for instance, than constancy in (Ecophora 

 does to expect constancy in Cerostoma. It is no new discovery that 

 the same character is fixed in one genus and variable in another ; 

 Darwin quotes instances (" Origin of Species"). Every genus and 

 species has to be judged separately on its merits ; and, in forming this 

 judgment, every careful worker, as Lord "Walsingham must be aware, 

 .is accustomed to examine a sufficient number of specimens to ascertain 

 variability, unless, indeed, he is unable to obtain them. Lord Wal- 

 singham has adduced one genus, in which veins 7 and 8 are sometimes 



