280 BRITISH ICHNEUMONS. | Luceros 


EUCEROS, Gravenhorst. 
Gr. I. E. iii (1829), 368 ; Ewmesius, Westw. Introd. ii (1840), Synop. 59. 
Head buccate and transverse; eyes oval and subprominent ; clypeus 
broadly discreted; lower mandibular tooth the shorter. Antennae a 
little shorter than the body; of 2 simple, of ¢@ centrally dilated and 
compressed with joints 11—17 much broader than the remainder. 
Thorax gibbulous. Scutellum subconvex, triangular and apically obtuse. 
Abdomen entirely sessile and subdeplanate, as broad as thorax with basal 
segment subquadrate and but slightly narrowed basally, remainder trans- 
verse ; Incisures deeply impressed; terebra not exserted. Legs somewhat 
slender; hind tarsi not explanate; tarsal claws pectinate. Wings sub- 
ample with no areolet; radius emitted before centre of the somewhat 
narrow stigma ; nervellus intercepted below its centre. 
This genus was founded by both Gravenhorst and Westwood on the 
centrally explanate @ flagellum, and the wanting areolet, to which the 
latter added the deeply impressed segmental incisures. The males are 
extremely distinct, but the females are not very easily recognised by their 
sessile abdomen, simple though pectinate tarsi, and quite concealed 
terebra. It was placed by its author under his supergenus Bassus, which 
differed from our Z7yphonides in its completely sessile abdomen, and the 
parasitism of the genus appears to warrant some such distinction from 
the majority of its group, in pertaining to the Lepidoptera. Many 
interesting details are given in Wesmael’s “ Note sur les caractéres des 
Euceros, Gray. (sous-genre d’Ichneumonides)” (Bull. Ac. Brux. 1841, 
p- 360). It is a small genus of some fourteen species, most of which are 
American ; five are palaearctic, and of these three or four are known as 
British. 
Table of Species. 
(4). 3. Body slender; abdomen centrally 
white-banded. 
(3). 2. Areola wanting; metapleurae and 
hind coxae black .. I. CRASSICORNIS, Grav. 
(2). 3. Areola entire ; metapleurae and hind 
coxae red .. : 2. SERRICORNIS, Had. 
(1). 4. Body stout ; abdomen not centrally 
white-banded. 
(6). 5. Hind femora and abdomen black ; 
scutellum basally white .. 3. UNIFASCIATUS, VodJ. 
(5). 6. Femora and abdomen, except basally, 
red; scutellum black A . 4. ALBITARSUS, Cur?. 
nm Se W 
1. crassicornis, Grav. 
Eucerus crassicornis, Gr. I. E. iii. 370, ¢; Shuck. Burm. Man., frontisp., 
fig. 2; Curt. B. E. 660; Blanch. Hist. Ins. iii. 321; Holmgr. Sv. Ak. Handl. 1855, 
p. 385, ¢ ¢3 cf. Verhoeff, Ent. Nachr. 1892, p.4. E. morionellus, Holmgr. Sv. 
Ak. Handl. 1855, p.201, ¢. E. pruinosus, DT. Wien. Ent. Zeit. 1890, p. 139, ¢ 
(? nec Grav.). 
A shining, black and white- or flavous-marked species, not at all red. 
Head of @ flavous with the eyes, vertex and occiput black; of ? black 
with the mouth partly, a central facial mark and another on either side 
