280 
Acantliia lectularia 
Legs : strong; coxae 1st pair close together ; 2nd and 3rd pairs 
laterally distant. Thighs alj subclavate, thickest at the base. 
Tibiae of equal size throughout. 
Tarsi 1st joint short; 3rd longer than 1st and 2nd together ; claws 
long. 
Abdomen : oval, flat, base much wider than pronotum, connexivum 
very narrow. Greatest breadth rather behind middle. Underside on 
the second segment in the middle a long thick trapeziform flat plate, 
directed forwards and joined to the plate of the mesosternum. In the 
male a ridge extends from each side of the plate as far as the fourth 
segment.” 
The following is their detailed description : 
Acanthia lectularia. 
“ Red-brown, clothed with fine short yellowish hairs, and generally 
covered with white dust. 
Head and pronotum finely punctured. Elytra with large deep 
distinct punctures. 
Abdomen mottled with black; above perceptibly crenate-punc- 
tate, beneath shagreened.” 
The black mottling of the abdomen is, in the writer’s experience, 
due to faecal specks, and is not inherent in the chitin as no trace of it 
can be seen in cleared specimens. 
External Anatomy. 
In general appearance the bed bug is small, flattened and bristly, 
about 5 mm. long and 3 mm. broad (Fig. 1). Both shape and appear¬ 
ance, however, vary according to the period which has elapsed since 
the last meal. The insect when famished being more or less circular 
and flat, while when fully fed it both lengthens and thickens. A fasting 
adult is of a dull amber to chestnut brown, but when fed it shows 
glistening bands of a highly polished brown, modified of course by the 
colour of the blood ingested. These bands are due to the stretching of 
the bug, which exposes the underlap of the segments, this being smooth 
and not rugose like the portions which are ordinarily exposed. In 
colour the creature varies from light straw when immature, to dark 
chestnut brown when adult; and as commonly met 'with, it is often 
thickly incrusted with dirt which has caked on its surface, the dirt being 
faecal matter evidently deposited on it by others, owing to their habit 
of huddling together in the darkest corners. They are often found 
