1918.] BASHAMBAR Das: The Aphididae of Lahore. 173 
presence of capitate hairs is rather a deviation from the generic characters, but they 
ate confined to the apterous forms only. 
Passerini has described a species of Phorodon on Cannabis, but the accounts of 
these insects by older writers was confined chiefly to the superficial characters which 
are often not very reliable. Aseven these earlier accounts are not available in English, 
I have prepared the description of the insect as found in the Punjab. 
It is likely that the Italian and the Indian insects are identical, so I have adopted 
Passerini’s name for the present instead of proposing a new one. 
CLUB-CORNICLED APHIDS. 
A short notice of the history of the genera Rhopalosiphum (Koch) and Siphoco- 
vyne (Pass.) might well precede the accounts to be given in the following pages of 
some Indian Aphids that are related to them in a way, though differing in several 
important respects. 
The genus Rhopalosiphum of Koch was first split up by Passerini into two groups. 
One set of species had antennae placed directly on the head, and the other carried 
them on frontal tubercles. Koch’s name was retained for the latter, while Szphocoryne 
(Pass.) was proposed for the former (Aphidae Italicae, 1863). ‘‘ Rhopolos’’ and 
‘““Coryne’ both mean a ‘‘club’’ and refer to the swollen or clavate character of the : 
cornicles or ‘‘ siphunculi.’’ 
The indistinct presence or absence of frontal tubercles is often confused, and it 
becomes a matter of individual opinion whether a particular species should be put in 
one or the other genus. 
Monell suggested an amalgamation of the two genera which was not ee 
and Lichtenstein (1885) who followed Passerini defined the genus Siphocoryne thus :— 
(x) Antennae implanted directly on head, non-hairy, with seventh joint dis. 
tinctly longer than sixth. 
(2) Nectaries long and clubbed. 
Buckton (Brit. Aphid. 1887) held similar views and remarked that the genus 
partook the characters of Aphis and Rhopalosiphum. Oestlund (Aphid. Minnesota, 
1887) further added that these characters were accompanied by the third antennal 
article being very ‘‘tuberculate”” and the species attacking unbelliferous plants. 
This is not true for all species. 
Van der Goot (Zur Systematik der Aphiden, 1913) has furnished a definition on 
morphological grounds and separates the two genera thus :— 
Frontal tubercles well defined ; a few sensoria on article III always present, in 
case even of the apterous female. Rhopalosiphum. 
Frontal tubercles indistinct or absent; sensoria in case of the apterous female 
always absent. Cornicles clubbed in both. Siphocoryne. 
Evidently here no notice is taken of the relative lengths of the antennae, body, 
cornicles and cauda, etc. 
It is of interest that Walker very early pointed out and erected a new genus 
