40 T. THORELL, 
higher degree the Attoide, distinguish themselves by their well proportion- 
ed forms, their powerfully developed cephalothorax, by the quickness and 
force of their movements, highly developed organs of sight, and the Atto- 
ide also by an expression of intelligence, which cannot escape even the 
most casual observer, and which, among other lower invertebrate animals, 
is only to be found in that Order of Insects which comprises undeniably 
the most highly developed animals of this Class, the Hymenoptera. As 
regards the other reasons that have been adduced in support of the as- 
sumption of the preeminence of the Epeiroide before all other spiders, 
such as the numerousness and beauty of the species, the small number of 
transition-forms, ete., they hold equally true of the Attoide, which form a 
unit quite as close, compact and rich in species as the Epeiroidæ; in the 
brillianey and variety of their colours they surpass both these and the 
other families of spiders, and may even be compared with the most showy 
families of Coleoptera, so distinguished for beauty and brilliancy of colour. 
If it is difficult to agree on, which group of spiders is to be consi- 
dered as the highest, it is on the contrary easy enough to determine which 
of the sub-orders received by us occupies the lowest rank. We without 
hesitation assign that place to the Tubitelariæ, among which, it is true, 
clear and defined transition-forms to lower groups of animals are as little 
to be met with as in any of the other sub-orders, but which nevertheless 
show themselves in many respects to stand in a lower stage than the other 
great subdivisions of the Order. The gradual reduction of the organs of 
vision is already one evidence of this: most of the spiders, that have only 
six eyes belong to this sub-order, and it is only within its compass that 
species have been found having only two eyes (Nops), or even totally 
mere connecting link between two other orders of Arachnoidea, but appears to have 
been developed side hy side with the so-called Arthrogastra (Solifugæ SUND.) from 
an inferior group, probably the Opiliones. In the families of the Scytodoidæ and 
Filistatoide are several features that may be considered to indicate relationship with 
the last-named order, as for ex. the process at the extremity of the mandible, whieh 
in conjunction with its claw almost forms a two-fingered forceps; the extraordinarily 
long legs of Polcus, the tarsus divided into three parts, ete. — Hacxen (Gene- 
relle Morphologie d. Organismen, II, p. xcvır) believes that spiders were developed 
from the Galeodoide, independently of the other divergent branches which, accord- 
ing to his view, go out from the Galeodoide, viz. Scorpiones (including Phrynus) and 
Opiliones; he considers the Saltigrade as the spiders, which still stand in the near- 
est relation to the Galeodoidæ, probably on account of the apparent segmentation 
of the cephalothorax in the genus Myrmecium. I can however in no wise accede to 
this opinion. 
