1879. 43 



vath's thoraeicus, yet the autennse are said to be " maxime ex parte flavis," wliieh 

 may do for our thoracica, but scarcely for Horvath's thoracicus — " antennis flavis, 

 articulo quarto toto dimidioque apicali articuli tertii nigris ; and Fieber and Dougl. 

 and Scott, as well as Flor, are cited for Schummers thoracica. 



Schummel says he had six ^ and twenty-one $ examples of his thoi-acica, 

 which was a rather common species in Silesia, and I know not if Dr. Horvath has 

 had access to any of them ; he only says of his snecies that it is considerably dis- 

 tributed in Mid-Europe, yet he had seen only one $ from Hungai-y. The result of 

 reference to the descriptions cited seems to me to be that only Flor's (and perhaps 

 Sahlberg's) species appears to coincide with Horvath's t/ioracicus ; that the thoracica 

 of Schummel, Fieber, H.-Schaffer, and Douglas & Scott are the same ; and that 

 Horvath's, Flor's (and perhaps Sahlberg's) thoracica is the species to be re-named. 



Horvath has adopted the genera into which Stal divided Oerris, Fab. {Hydro- 

 metra, Auct.) — Limnotrechus, Hygrotrechus, and Limnoporus {quantum valeant !) — 

 but he has rightly used Hydrometra, Latr., instead of Limnohates, Burm. On the 

 extraordinary confusion which has existed in the application of the names Gerris 

 and Hydrometra, see the remarks of Pascoe and Douglas & Scott in the Ann. and 

 Mag. of Nat. Hist., 1868 ; Dallas in the Zool. Eecord, v, 393 (1869) ; and Douglas 

 in Ent. Mo. Mag., xii, 224 (1876). — J. W. Douglas, 8, Beaufort Gardens, Lewisham ; 

 2nd June, 1879. 



The genus Aleurodes. — Since my note on this subject (vol. xiv, p. 230), I could 

 not report anything satisfactory about British species, having been disabled during 

 last summer and thereby precluded from making much personal investigation. In 

 June a friend wrote that he had found plenty of celandine growing near Box Hill, 

 Surrey, but saw not a trace of A.proletella, and this was all I learned of this species. 

 Another friend, who had previously told me that he doubted if there were so many 

 species as reputed, in July caught one individual, which flew into his room, and sent 

 it to me, but it never arrived. He at once visited his cabbages, having, in a former 

 year, seen Aleurodes abundant thereon, but now none were to be found, and his absence 

 from home afterwards prevented any resort to his " kail-yard." Search among my 

 own cabbages gave a similar result, and so ended my hopes of getting A. hrassicce in 

 situ. But in August, on the other side of my garden, I took several examples of a 

 perfectly white sptcics, whose custom of a:i afternoon was to fly over a strawberry- 

 bed, and sometimes I saw one on a strawberry plant, but neither then nor previously 

 could I detect any trace of a larva thereon. This species cannot be A. fragaricB, 

 which Walker says has one spot on each wing, nor A. brassiccB, which has two spots on 

 each wing. On 31st July, in a lane between gardens at Lee, there was flying in consider- 

 able numbers a spotless white species, apparently the same as the last mentioned, 

 but I failed to trace them to any particular plant. On October 13th, on the aforesaid 

 strawberries and flying over them, I obtained some examples of white Aleurodes with 

 a faintly dark spot on each upper wing, apparently of a species diiierent to that I had 

 previously found at the same place, and failing the knowledge of the larva) (which, 

 however, I had diligently sought), the question occurred — Are these the progeny of 

 the pure white brood I had seen in August ? Lastly, on October 2nd, I saw a similar 

 spotted-winged species abundant in Darenth Wood, on all kinds of plants, but I could 

 get no hint of their food plant. Are both these A. fragarice ? 



