NEW AND LITTLE KNOWN BRITISH APHIDES. 238 
Food plant.—Goat Willow (Salix capree). 
Locality.—Inveran, Invershin, N.B. (8 . ix . 20) (D. J. 
Jackson Coll.). 
Observations.—Described from mounted specimens and live 
colour notes sent me by Miss D. J. Jackson, who found this 
insect thickly clustering along the branches of a goat willow 
growing in a birch wood, in company with P. populeus. It was 
closely attended by ants (Mormica rufa), that had many nests in 
the locality. The Aphides harmonised closely with the colour 
of the branches. This species closely resembles populeus, but the 
antenne of the apterous female carry marked round sensoria, 
and the hairs of the legs are much closer and slope towards the 
apex of the leg, whilst in populeus (pilosa) they are further apart 
and more erect. The prothoracic papille are very marked, 
being truncate, but in one specimen one papilla is rounded 
apically, the other being markedly flattened at the apex. 
Pterocomma fraxini, nov. sp. 
Apterous viviparous female.—Dull reddish-brown, with dark 
median and lateral patches, from which very small tubercles arise 
and also on the pronotum. Antenne reaching just past the third 
pair of legs; two basal segments dark; third and fourth pale, dusky 
at apices; fifth and sixth dark; basal segment larger than second; 
third about twice as long as fourth, which is about equal to fifth; 
sixth with flagellum twice as long as basal area (unlike P. popwlews) ; 
hairs long, fairly numerous, but not so much so as in populeus, pale 
on third segment, darker elsewhere; sensoria on fifth and sixth 
normal. Cornicles projecting and about as long as fifth segment, 
nearly twice as long as the hind tarsals, swollen apically on one side 
and constricted near or at apex; dull yellowish, dusky at apex. 
Cauda dark, rounded; anal plate paler, both hairy. Legs pale to 
deep yellowish-brown, fore and mid femora and tibiz thick, apices of 
tibie broad and truncate; tarsi narrow; apex of tibix dark. 
Antenne, body and legs very hairy. 
Length, 3-9 mm. 
Locality.x—Wye (3 . vi. 11). 
Observations.—Described from a single colony found on the 
petiole of an ash leaf (F'raxinus excelsior). It is more robust than 
Pterocomma populeus, from which it also differs in (1) the longer 
and larger cornicles and (2) the long flagellum to the sixth 
antennal segment. It most nearly approaches P. bicolor of 
Oestlund, but the cauda is not broadly angulated. ‘The thick 
legs are very characteristic. 
