GENERIC CLASSIFICATION OF APHIDIDAE. 61 
Genus PENTALONIA Coquerel. 
Plate VIII, II-MM. 
1859. Pentalonia Coquerel, Ann. Ent. Soc. France, Ser. 3, v. 7, p. 259. 
The genus Pentalonia Coquerel is a very peculiar one and possesses 
a venation unlike that of any other in the Aphididae. It is, however, 
only a little further development of the condition met with in 
Idiopterus, which is the less specialized of the two genera. 
Characters-. — Head with prominent antennal tubercles which are, more especially 
in the apterous form, projected inward, gibbous and somewhat Myzus-like in appear- 
ance. Antennse of six segments, armed with subcircular sensoria, the first segment 
gibbous like the antennal tubercles. Cornicles somewhat constricted near their 
middle, then again somewhat swollen near their distal extremity. Cauda rather small 
but elongate, subcorneal, slightly constricted about the middle. Fore wings with the 
radial sector extending abruptly downward and meeting the upper branch of the media 
with which it fuses but is diverted again toward its natural course near the tip of the 
wing. A closed cell is thus formed by the radial sector and the media but at the 
margin of the wing there are the same veins as in the Aphidini (Plate VIII, JJ.) 
Hind wings very much reduced, cubitus absent. 
Type (monotypical) , Pentalonia nigronervosa Cql. 
Subfamily II, MINDARINAE. 
It has been the custom to consider the genus Mindarus as closely re- 
lated to the Pemphigini, but the writer is unable to do this and concludes 
that it must represent a subfamily in itself. In some ways abietinus 
is the most primitive living aphid. It is, in fact, the only one which 
has retained the general wing structure which is predominant in the 
fossil forms. It is true that the venation is more reduced than in 
some of the other subfamilies, but the type of wing in regard to the 
stigma formation is exactly like most fossil wings and unlike the 
wings of other living forms. Many of the characters suggest the 
Eriosomatinae and the genus is no doubt very similar to the ancestors 
of the insects in that subfamily. The antennal structure and general 
form are like those in the Eriosomatinae. The sexes, too, are apterous, 
but though they have developed the small apterous condition they are 
in many ways more primitive than are the sexes of the Eriosomatinae. 
The male is small and suggests the condition in those forms. The 
peculiar habit of copulation is similar, in that the male mounts the 
female and may remain there inactive for a very long period. The 
writer has observed a male of Eriosoma lanigerum clinging thus to a 
female for 48 hours. The sexes of Mindarus, however, have not 
lost the beak and the male feeds on the juices of its host. In this 
regard they are more primitive than sexes in the Eriosomatinae. 
The oviparous female, moreover, develops her ovaries and produces 
as high as 8 or 9 eggs, in striking contrast with the ovipara in the 
Eriosomatinae. It is a much less specialized condition. In regard 
to the alate form the shape of the cauda is quite different from that 
met with in the Eriosomatinae. 
