102 
THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
the numerous and great difficulties by 
which the undertaking is surrounded. 
“Although a large addition has re- 
cently been made to the knowledge of 
our native species of Araneidea, yet the 
subject is far from being exhausted ; a 
wide field still remains to be explored by 
succeeding arachnologists ; and if the 
present work should tend to promote and 
facilitate the researches of others in this 
department of Zoology, one of the most 
important purposes it is intended to sub- 
serve will be accomplished. 
“ The difference in the number of eyes 
with which spiders are provided, sup- 
plying, as it does, well-marked characters 
not difficult to be ascertained, has been 
taken as the most convenient and satis- 
factory basis of their distribution into 
tribes. On this principle the three fol- 
lowing tribes have been founded, which 
include all the species hitherto dis- 
covered : — 
1. Octonoculina ; eyes eight. 
2. Senoculina ; eyes six. 
3. Binoculina ; eyes two. 
“The first tribe, Octonoculina, is much 
the most extensive of the three, com- 
prising numerous genera, which exhibit 
considerable differences in organization 
and economy ; the second tribe, Senocu- 
lina, includes ten or eleven genera, spe- 
cies belonging to many of which are 
found in this kingdom ; and the third 
tribe, Binoculina, contains the single 
genus Nops, instituted by Mr. W. S. 
MacLeay, for the reception of two re- 
markable species of extra - European 
spiders. It may be further remarked, 
that to the families previously established 
another has been added, namely, the 
Ciniflonidcc ; and that several new 
genera have been introduced, whose cha- 
racters are defined in their appropriate 
places. 
****** 
“ Linnanis and the naturalists of his 
school have included spiders in the ex- 
tensive class Insecta, having constituted 
with them the genus Aranea, comprised 
in the order Aplera. Subsequently 
zoologists have removed the Aranea and 
several nearly allied groups from the 
apterous insects, and have established 
with them the class Aracknida. Of 
this class the spiders form the order 
Araneidea, which is divided into tribes, 
families and genera. A concise sum- 
mary of the more important facts re- 
lating to the organization and eco- 
nomy of these animals, which have 
been disclosed by the researches of ana- 
tomists and physiologists, will serve to 
elucidate the history of species. 
“ Spiders, with few exceptions, have a 
cephalo-thorax, or the head continuous 
with the chest ; but the cephalic may 
readily be distinguished from the thoracic 
portion by the presence of the eyes, which 
are two, six or eight in number; by the 
falces situated in front, and terminated 
by a pointed fang, which has a gingly- 
moid movement; and by the oral appa- 
ratus connected with its inferior surface. 
Eight legs, of seven joints each, having 
two or more claws at their extremity, are 
articulated round the cephalo-thorax. 
“ All spiders at present known have 
two, six or eight smooth eyes, which vary 
much in size and relative position, sup- 
plying characters of great importance in 
the systematic arrangement of species. 
“ The falces, inserted immediately 
under the anterior margin of the 
cephalo-thorax, though modified in form, 
are, for the most part, subconical ; and 
have usually at the extremity of their 
