24 Rey. T. A. Marshall’s Monograph of 
segment oblong, a little narrowed at the base, striolate, pubescent, 
with more or less visible tubercles. Terebra briefly exserted, with 
broad, flattened valves. 
These insects are distinguished from Dacnusa by a 
certain facies, which is due to the form of the head and 
abdomen, as well as to the neuration. Fdérster has made 
of them two genera, Gyrocampa and Ametria, the latter 
of which is distinguished by a longer radial areolet, and 
the number of joints of the labial palpi. The same author 
evidently intended to separate Gyrocampa from Dacnusa 
by the radial nervure, which is regularly curved in the 
former; but the typographical errors in his synopsis, 
p- 276 (where No. 2U needs correction), are misleading 
to the reader. It may also be remarked that some 
species of Dacnusa, as D. semirugosa (sp. 4), present a 
radial nervure not more sinuated than in Gyrocam pa. 
The parasitism of the species of (ryrocampa is unknown, 
but they are always found in marshy places, especially on 
plants of the family Lemnacew. The dense pubescence 
or down, covering the region of the principal spiracles, 
viz., the metathorax and the Ist abdominal segment, is 
probably for the protection of the breathing-orifices from 
water, and indicates, as in many other insects, the habit 
of living in wet places. 
TABLE OF SPECIES, 
(4) 1. Labial palpi 4-jointed ; stigma attennated, but 
not quite obsolete, emitting the radial nervure 
at one-fourth of its length. 
(3) 2. Second segment striolate at the base, length 
nearly 2 lines ate nec ... 2. foveola, Hal. 
(2) 8. Second segment entirely smooth ; Tenth 1 line 
or very little more .. lL. affinis, Nees. 
(1) 4. Labial palpi 3-jointed; stigma obs slete, or "nearly 
so, not thicker than the costa, emitting the 
radial nervure at one-third of its length ... 3. wliginosa, Hal- 
Gyrocampa affinis, Nees. 
Bracon longicornis, varr. a, 8, Nees, Mag. Ges. Berl., 
LSI, pe 20, 
Bassus affinis, Nees, lib. cit., 1814, p. 209. 
Alysia affinis, Nees, Mon., i., p. 261, # 2. 
Dacnusa affinis, Hal., Hym. Brit., ii., p. 16, 2 2. 
G. affinis, Marsh., Species des Hym. d’Hur. et d’Alg. 
Bracon., vol. ii., p. 503, f 2. 
