THE ENTOMOLOGIST 



Vol. XXXVL] APRIL, 1903. [No. 479. 



SPECIFIC DIFFERENCES IN LITHOSID^, AS DETER- 

 MINED BY STRUCTURE OF GENITALIA.- 



By F. N. Pierce, F.E.S. 



Plate I. 



Lithosia sericea, Gregson, was first described by my old friend 

 C. S. Gregson, in a paper read before the Old Northern Ento- 

 mological Society on September 29th, 1860, and printed in the 

 'Entomologists' Weekly Intelligencer,' ix. p. 30, in which he points 

 out the difference between it, Lithosia complana, and L. compla- 

 nula; Guenee (Ann.Ent. Soc. France, 1861, 4th series, vol. i.p.50) 

 redescribes it under the name molybdeola. Both entomologists 

 take the shape and markings of the wings as sufficient to con- 

 stitute a new species, Guenee observing that the distinction of 

 the species must depend on the discovery of the larva. 



Sericea is peculiar to the Lancashire mosses, and as it has 

 not been found elsewhere, certain doubts have from time to time 

 been thrown on it being a good species. 



Buckler and Hellins (vol. iii. p. 20) appear to supply the con- 

 firmation required by Guenee and state that the larva of sericea 

 differs from complana in the subdorsal spots having no round- 

 ness whatever in their shape, but narrowish oblong, somewhat 

 wedge-shaped marks ; also that while in complana the spiracular 

 region is occupied by one broader rust-coloured line, in sericea 

 there are first a fine line of pale grey, then a line of the ground 

 colour, and then a narrower line of the rust colour. But even 

 this does not appear to satisfy everyone on their distinctiveness, 

 for Meyrick, in his 'Handbook of British Lepidoptera,' page 27, 

 states of sericea: "It is uncertain whether this is anything 



* Read before the Lancashire aud Cheshire Entomological Society, 

 Dec. 6th, 1902. 



ENTOM. — APKIL, 1903. H 



