200 [October, 



But, at p. 274 (under Lecanium JEmerici, Planchon), Signoret 

 says — 



" Dans le premiere parti de cet ouvrage (p, 23 and p. 250) je disais qu' Hmerici 

 etait connu et que c'^tait le quercus de Keaumur. En effet, planche v, fig. 2, il re- 

 presente une espece qui a la plus grande ressemblance avec Emerici ; cependant, 

 comme il indique lee ehenes ordinaires comme habitat, il est plus que probable que 

 ce n'est pas le meme." 



I agree with this ; Emerici, and all the other allied species which 

 Signoret refers to his genus Kermes, live only on Quercus coccifera or 

 Q. ilex in the South of Europe, while Lecanium fuscum lives only on 

 Quercus rohur. 



Signoret (l. c.) describes his Lecanium fuscus (of which he had 

 only a single example, taken from an oak at Vienna) thus : — 



" EUe est d'un brun marron, fortement ponctuee sur les cotes, lisse sur les dos, 

 demi-spherique, un peu etranglee vers I'insertion sur la brancbe." 



Now, "une sphere coupee en deux," or "demi-spherique," is not 

 the "rond" of Geoffroy nor the " presque spherique " of Keaumur, 

 and a restricted meaning is placed upon the remark of Geoffroy, " II ne 

 paroit pas differer de celui de I'orme," that the words do not warrant ; 

 therefore, whatever the "fuscus " of Signoret may be, it is not the 

 species of Geoffroy, to whom he attributes it, nor of Eeaumur, which 

 is all that I am noAv concerned to show. 



The conclusion of Planchon, as expressed by Signoret, p. 274, 

 " La plus grande confusion n'a cesse de regner sur les especes vivant 

 sur le chene, ce qui n'est pas etonnant, a cause de leur ressemblance " 

 is very just.* It is now not possible in many cases to identify a 

 species so surely as to be able to give due credit of priority of name, 

 mainly by reason of the too succinct or imperfect description and 

 account of similar species given by former authors. In fact, among 

 the GoccidcB, especially in the Lecanidce, where the appearance varies 

 greatly during the course of the life of a species, the insect should be 

 closely observed in all its stages, in order to form a correct idea of 

 specific character. 



On June 24th, Mr. G. C. Bignell, of Stonehouse, Devon, sent 

 me, from an oak in his district, some scales, described above (six of 

 the spheroid form and two of the oblate-spheroid), all, except this 

 slight deviation, being otherwise exactly alike ; and with them the 

 following information : — 



• " II rfgne k cet rgard, daiiS les ouvrages des auteurs modernes, de singuliferes confusions. 

 Les uns altferent les vrais caractferes dii Kerm&s, en y ajoutant des particularit^s qui n'appartien- 

 nent qu'aux especes voisines : d'autres, allant encore jjIus loin, negligent ces caract^res pour y 

 substitTuer ceux d'espfeces differentes De Ik resulte une confusion que peuvent scules faire cesser 

 les observations directes." Planchon " Le Kermfes du chene," p. 17. Paris, 1864. 



