4 Mr. MacLeay on some new forms q/" Arachnida. 



of the egg-shaped cephalothorax. The sternum has vestiges 

 of those eminences at the base of the feet which distinguish 

 Ariadne and certain American forms of Dysdera. This spi- 

 der has only two pulmonary pouches ; or if it has four, the 

 additional ones are very small. It is common under stones in 

 woods ; and occurs also, although more rarely, in houses. I 

 have never seen it making a web, so that in this respect it 

 agrees wath some of the Drassi. In fact, it connects the Dys- 

 derina, such as Savigny's subgenus ^riac?we, with certain Dra*- 

 sina, such as Savigny's subgenus Lachesis. 



The Dysderina form a curious group. In them not only have 

 we the eyes varying in number, two, four, six, or eight, but the 

 organs of manducation are in some species rudimentary, and 

 in others excessively developed. I possess specimens of a 

 translucid West Indian spider closely allied to Filistata, and 

 having Mygalidous eyes situated on the balloon-shaped cepha- 

 lothorax of a Nops. In these specimens the antennae, max- 

 illae, &c. are so rudimentary and inconspicuous as would al- 

 most make us doubt that the species can be an animal of 

 prey, did we not find it making an irregular web in the cor- 

 ners and crevices of houses. I call it Hemerachne tenuvpes ; 

 and on viewing it we can the better understand how Nops and 

 Ariadne should have small antennae, while Dysdera erythrina 

 has these organs so large. 



I place Nops among the Dysderina^ and not among the Dras- 

 sina, on account of its hard tegument ; for the Drassina in ge- 

 neral have this very tender, and thus we see Clubiona and 

 other comparatively delicate genera not only to form the food 

 of Hymenoptera like Pelopceus^ but even of Diptera. I have 

 caught various species of Asilidce in the act of devouring 

 these tender-skinned spiders, so that if certain spiders live on 

 flies, there are also certain flies that feed on spiders. But to 

 return to Nops Guanahacoce, the figure I give of it was drawn 

 by Mr. Charles Curtis fi.*om a dried specimen in my cabinet, 

 and coloured from a sketch made by me in Cuba of the live 

 animal. I possess another species of the genus which has no 

 black spot on the cephalothorax. 



I take this opportunity of saying that I shall be glad to ex- 

 change specimens of iVo^^for specimens of the genus Artema, 



