328 Mr. F. Walker’s Descriptions of Aphides. 
with which I am acquainted, I do not see how it can be placed 
in any other genus. 
Grammitis hlechnoides (nob.) ; fronde coriacea, utrinque attenuata, 
profunde pinnatifida, soris lineari-oblongis, subobliquis, numerosis. 
Fronds numerous, from a creeping rhizoma which is densely 
covered with pale reddish brown scales, lanceolate, coriaceous, 
glabrous, seven to nine inches high, attenuated at each extremity, 
pinnatifid almost if not quite to the rachis, the segments alter- 
nate, entire, linear, obtuse, about half an inch long in the widest 
part of the frond, diminishing gradually in size below until they 
disappear a few lines from the rhizoma. Veins simple, internal. 
Sori oblong or linear- oblong, slightly oblique, arranged in a line 
on each side between the midrib and the margin, somewhat sunk 
in the thick substance of the frond. 
EXPLANATION OF PLATE XVIII. 
Fig. 1. Grammitis hlechnoides , natural size. 
Fig. 2. One of the segments, a portion of its substance removed to show the 
venation. 
Fig. 3. Sori. 
Fig. 4. Capsules. 
Fig. 5. Seeds. — Figs. 2-5 magnified. 
XXXVI. — Descriptions o/ Aphides. By Francis Walker, 
F.L.S. 
[Continued from p. 260.] 
Fourth Group. 
The chief peculiarity of the only species in this group is the 
abundance of cottony filaments which emanate from its body, 
and it resembles the preceding Aphis in the shortness of its nec- 
taries and of the seventh joint of its feelers. 
6. Aphis Fagiy Linn. 
Aphis Fagij Linn. Syst. Nat. ii. 735. 23; Faun. Suec. 994; 
Geoft*. Ins. i. 497. 12 ; Reaum. Ins. iii. t. 26. f. I ; Fabr. Ent. 
Syst. iv. 214. 24; Syst. Rhyn. 297. 24; Burm. Handb. der 
Ent. ii. 92. 2. 
Lachnus Fagi, Kalt. Mon. Pflan. i. 147. 1. 
The viviparous wingless female. This appears on Fagtts sylva- 
tica, the beech, before the end of April ; as soon as it is hatched 
from the egg it resorts to the veins of the young leaves, and is 
then pale green or yellow, very small, long, narrow, slightly con- 
vex, nearly linear, or somewhat increasing in breadth towards the 
tip of the abdomen ; its sides are covered with white filaments : 
the feelers are filiform or slightly setaceous, dark green, paler at 
