264 Transactions.— Zoology. 
It scarcely needs more than a glance, however, at the lip and maxille to 
decide that this interesting spider does not belong to Argyroneta, but, 
indeed, that in the form of these appendages it differs very strikingly from 
that genus. Dr. L. Koch deseribes two closely allied species (Arachniden 
Australiens, p. 345-351, plate xxix., figs. 1 and 2) referring them to the 
genus Desis, founded by Walekenaer on a single species, Desis dysderoides 
from New Guinea. 
The following are the characters of the genus Desis, as given by 
Walckenaer.* 
“Eyes eight, in two lines, the anterior very close to the anterior margin 
of the cephalothorax, curved backwards, and forming an open crescent; the 
eyes forming the intermediate square, larger than the lateral eyes, which 
are situated on a-slightly raised tubercle. 
** Lip elongated, with parallel sides, deeply notched at its extremity. 
* Maxille straight, diverging, dilated at their base, pointed at their 
extremity. 
** Legs strong, suited for running; the anterior longer than the posterior ; 
the first pair the longest, the second next, the third pair the shortest.” 
The above characters are supplemented in the description of the species 
Desis dysderoides, which I subjoin. 
«Abdomen oval, convex above and below, of a uniform pale grey. Cepha- 
lothorax, mandibles, sternum, legs and palpi coral red. Mandibles long 
and strong, directed forwards. 
“New Guinea. Quoy and Gaimard. 
** Aspect of Dysdera erythrina. Cephalothorax as long and as large as the 
abdomen, sides almost parallel, scarcely at all narrowed anteriorly, flattened. 
Sternum without spots, without eminences, and clothed at the insertion of 
the legs with yellow hair. The mandibles are very strong, directed forwards 
as in Dysdera, as long as the cepthalothorax, eylindroid, with the claws of 
a red brown, elongated, half opened and not completely folded back in the 
groove, which last is toothed. The teeth are prominent and number eight 
or nine as in Dysdera erythrina. The legs have the tarsus provided with 
three claws, of which one is very short and almost hidden in the hairs." + 
The agreement of our spider with the above characters is so close that 
there can be no doubt as to the propriety of placing it in this genus. 
= Desis robsoni, nov. sp. 
Male.—Cephalothorax moderately dark mahogany brown, darkening 
towards the facial border, paling towards the sides and posterior border of 
the thorax, Map clothed with short hairs. Angle of the caput bor- 
dered with 
—— 
* Histoire des Aptéres, Vol. I, p. 610, plate iv., figs. 15 a and b. 
+ Histoire des Aptéres, Vol. I., p. 611, 
AA Ua LESSONS MEESCIBVEE E AE EE E EEEN N EE E I EE A SS LEA A AAR A RE O BDE OEE EAEE E 
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