84 T. THORELL, 
Linyphia passes gradually into Walckenaera (Micryphantes), and only 
a tolerably artificial limit can be established between these two genera, 
however unlike each other they on the whole may be. We admit, with 
WESTRING, that the presence of scattered spines on the legs is the mark which 
distinguishes Linyphia from Walckenaera (and Erigone), in preference to the 
distinction proposed by OHLERT, the presence of palpal claws in Linyphia, 
and the absence of them in Walckenaera (and Erigone). In fact, the cha- 
racter deduced from the spines on the legs is easily verified, whereas the 
palpal claw in some of the smaller Linyphiæ is so fine and slender as to 
be very difficult to distinguish from an ordinary bristle, and furthermore the 
presence or absence of a claw on the palpus is a characteristic applicable 
only to one sew, the female. Besides, Ærigone vagans Say. et AUD. is said 
to be, unlike other species of that genus, provided with a palpal claw +), 
and of the genus Ceratina MENGE, which we unite with Walckenaera or 
Micryphantes, C. brevis, according to MENGE (as well as Wesrrine’s Eri- 
closely related in every thing else (e. g. the species of the genus Zilla (Koch) 
Wesre.) show very considerable differences with respect to the organs in question, 
and this has caused newer arachnologists with predilection to deduce the distinctions 
of species from the almost endlessly varying forms of the palpi of the males and the 
"epigyne" or vulva of the females. — Science however must necessarily gain by every 
endeavour after an improved classification and a sharper distinction of the genera of 
spiders. It is indisputable, that Arachnology stands in a much lower position than 
most other branches of Entomology, and that especially the scientific diagnosis of fa- 
milies and genera is as yet very defective. More than one arachnologist of the pre- 
sent time content themselves with WALCKENAER'S system, and follow in their deserip- 
tions the method of that princeps arachnologorum, whose honour one by no means 
depreciates by not believing, that the science ought always to remain stationary at the 
point, to which he carried it and where he left it. Only a few of the few, who de- 
vote themselves to this branch of zoology, labour to promote it by other means than 
by inereasing the number of better or worse descriptions of species. Of late years 
however signs of a better spirit have shown themselves, and among the works which 
rise above the ordinary level, those of MENGE undoubtedly occupy a particularly 
high place. But many workmen are still wanted upon that so slightly cultivated 
field, and in order to obtain these, it is necessary in the first place to make fauni- 
stie and descriptive works in general as easy to use and as practical as possible. 
As long as good and suffieient marks of distinetion ean be found by the aid of the 
simple magnifying lens, one must not make the compound microscope an indispensable 
instrument for any one, who may wish to determine the name and systematie posi- 
tion of an unknown spider. That the microscope is not necessary in order with cer- 
tainty to distinguish even the smallest speeies of spiders, is fully evideneed by the 
works of WESTRING and OHLERT. 
1) Descript. de l'Égypte, Arachn., (Éd. 2:) XXII, p. 320. 
