456 
ARACHNIDA. 
were not known in Italy, we consider with Mouffet that the Lycosse, and other large Spiders which 
do not construct wehs, as well as the Solpugae, are the animals collectively known under the former 
name, and of which several species were described hy the ancients. Lister, who first studied the | 
Spiders which inhabit Great Britain with great care, laid the base of a natural distribution, of which 
those more recently published are mostly only modifications ; our more recent acquaintance with some 
species peculiar to warmer climates, such as as the Mason Spider, described by Sauvages, and other 
analogous species, the employment of the organs of the mouth, introduced by Fahricius, a more pre- 
cise study of the eyes and their relative sizes, and the relative length of the legs, have contributed to 
perfect their arrangement. M. Walckenaer has entered into very minute details relative to these 
animals, so that it is difficult to detect a species which wiU not enter into the groups which he has 
proposed. The presence or absence of a third unguis at the extremity of the tarsi affords another cha- 
racter not yet sufficiently generalized, of which, however, Savigny has given a slight sketch (see 
Walckenaer, Faun. Frang., note at the end of the genus Attus). 
M. L. Dufour, who has published excellent memoirs upon the anatomy of these insects, and 
especially studied those of the kingdom of Valencia, where he has discovered many new species, has 
paid particular attention to the respiratory organs of the Arachnida, and it is after his remark that we 
divide them into those which have four pulmonary sacs, with four external spiracles, two on each side 
close together, and those which have only two.* 
The first of these groups, which includes the Araneides tTieraphoses of Walckenaer, and some genera, 
for which he has employed the collective name of Aranea, compose, in our method, the single genus— 
Mygale. 
The eyes are always situated at the anterior extremity of the thorax, generally close together. The 
chelicerffi and legs are robust. The majority have only four spinnerets f ; the two lateral ones are situ- 
ated rather above the two others, and are longer and 3-jointed, not computing the elevation which 
forms their footstalk. They form silken tubes for their abode, which they hide either in the earth 
into which they have burrowed, or under stones, in the bark of trees, or amongst the leaves. 
The TherapJioses of Walckenaer form a first division, characterized by four spinnerets, the two inter- 
mediate and inferior generally very short, and the two exterior much exserted ; the hooks of the 
chelicerse folded beneath, along the under side, and not along the inner surfaces. Eight eyes in all, 
generally arranged upon a small eminence, three on each side, forming a reversed triangle, of which 
the two upper ones are close together; the two others in a line between the preceding. The fourth 
pair of legs and then the first pair are the longest, the third the shortest. 
Those species which have the palpi inserted at the superior extremity of the maxillae so that they appear to he 
six-jointed, the basal joint being long and narrow, and acting as the maxilla; the tongue, always small, 
and nearly square, and the two fore tibiae of the males with a strong spine beneath at the tip, form the restricted 
genus — 
Walck,,— some of which have not a transverse series of moveable, corneous spines at the upper 
extremity of the chelicerae, above the place of insertion of the terminal hook. The hair on the under-side of 
their tarsi forms a thick cushion, generally hiding the ungues. These are the largest species of the family, some 
* [The arrangement of the Spiders given by M. Walckenaer, in his last work, above referred to, differs in some respects from that employed 
by Latreille. The following is an abstract of his tabular synopsis 
Groups arranged ac- 
Genera. cording to the na- 
ture of their nests. 
f Eyes near together . . Mygale, Filistata, &c. 'l-Latebricoles 
Eight eyes 4 Ryes apart Missulena 
1 Eyes frontal Dysdera, &c Tubicoles . 
Six eyes . Ryes frontal and lateral . Uptiotes, &c Cellulicoles 
Eyes frontal and lateral, 1 Lycosa, Dolophones, &c. Coureuses . 
unequal J Eresus, Attus, &c 
Araign^es . 
Eight eyes 
Voltigeuses 
Thomisus, Sparassus, &c. Marcheuses 
■Vagabondes 
Sedentaires 
Nageuses . 
Aquatiques.] 
^J.110UU6U»9 ojjaittoauo, v.ia'-w.mv.u 
I Clubiona, &c Niditeles . 
Pholcus, &c. .... . Filiteles . 
, , , . , Tegenaria (Aranea), &c. Tapiteles . 
Eyes frontal, equal-sized-^ Epeira, &c Orbiteles . 
! Linyphia Napiteles . 
Argus, &c Retiteles . 
t ''Argyroneta Aquiteles . 
[Mr M'Leay, in an article upon some new forms of Arachnida, published in the Annals of Natural History, has thrown doubts upon the 
general character given of these groups, figuring one species with only two eyes (Nops Guanabaco^) ; another, with 
fhree distinct segments, and one pair of the eyes enormously large {Deinopis Lamia) ; another with the head thorax, and abdomen apparently 
articulated {Myrmarachne melanocephala) ; and another with the fore-legs modified, in structure short, thickened, and composed of only six 
instead of seven joints (Oftoffiops fFiifcftewaeri).] , . .. • • , j 
+ I have observed in Atypus the vestiges of two other nipples, being those which in the Spiders of the following division are placed between 
the four exterior ones, and are very visible [ but as they are here scarcely apparent, I have not counted them as such. 
