Guide to Arachnida. 
Table-case 
No. 22. 
Wall-case 
No. 7. 
Table-case 
No. 23. 
96 
Fam . — A typidae. 
The two genera ( Atypus and Calommata ) which compose this 
family differ from the Avicnlariidae and Ctenizidae in possessing 
a large maxillary process upon the base of the palp. The chelicerae 
are not usually furnished with digging spines. 
The genus Atypus has a wide distribution, occurring in 
Europe, North Africa, Japan, Burma, and Java ; whilst Calommata 
is found in Japan, Burma, the Sunda Islands, and West Africa. 
The only Mygalomorph spider 
which occurs in this country [Atypus 
affinis) belongs to this family. It is 
found in the South of England, the 
Channel Islands, and also in Ireland, 
and many places on the Continent. 
The nest of this spider consists of a 
long burrow, excavated in the ground, 
and lined throughout with web. This 
lining is continued beyond the surface 
as a long closed tube, which is either 
attached to some object near at hand 
or lies loosely on the surface of the 
ground; when flies or other insects 
alight on it they are seized from within 
by the spider, and pulled through the silk, the rent thus made 
being repaired afterwards. Similarly, the male enters the burrow 
by biting a hole in the wall of the tube. 
A number of the external tubes of the North American purse- 
web spider ( Atypus abboti ), which are spun against the trunk of a 
tree, are exhibited in Wall-case 7. 
Tribe ii. — Arachnomorphae. 
In these spiders the outer branches of the anterior pair of 
spinning appendages and both the outer and inner branches of 
the posterior pair are present, the inner branches of the anterior 
pair being often represented by a perforated spinning-plate (the 
“ cribellum ”) or by a membranous lobe (the “ colulus ”). In the 
spiders in which the “ cribellum ” is present, the penultimate joint of 
the fourth leg is always furnished with a series of curved hairs. The 
chelicerae project downwards. The posterior pair of pulmonary 
sacs is replaced (except in the genus Hypochilus) by tracheal tubes, 
the stigmata of which may be situated immediately behind those of 
