82 A Guide to the Zoological Collections in the 



Trap-door Spiders My gale and Scurria in Case 60, these 

 being types of the order A raneida or true Spiders. 



In these the segments of the head and thorax are 

 consolidated to form a cephalothorax, which is enclosed in 

 a firm chitinous integument and bears six pairs of " append- 

 ages ", — the first pair, or "chelicerae", or jaws, ending in 

 fang-like poison-claws placed on either side of the mouth j 

 the second pair being many- jointed "palpi", or feelers, 

 the basal joints of which are expanded to form a second 

 pair of jaws ; and the remaining four pairs being long 

 many-jointed legs. On the dorsal (upper) surface of the 

 cephalothorax, towards the front and sides, are eight (in a 

 minority of Spiders six) large simple eyes. Behind the 

 cephalothorax, and attached to it by a narrow stalk, is the 

 large soft swollen abdomen, in which, in the adult, no signs 

 of segmentation can be detected. On the under surface 

 of the abdomen, in front, are seen the two pairs (in the 

 great majority of Spiders, however, there is only a single 

 pair) of slit-like orifices of the tracheal sacks, or "lungs". 

 At the end of the abdomen, round the vent, are seen the 

 wart-like eminences upon which the spinning-glands open, 

 two of these in Mygale and Scurria being of great 

 length. 



In the Spiders the female is usually very much larger 

 than the male. 



The rapacity and voracity of Spiders is well known : 

 some, such as Mygale^ lie in wait for their prey in burrows 

 in the earth, the mouth of the burrow being provided with 

 a hinged lid (Trap-door Spiders) : others, such as Lycosa^ 

 run their prey down : others, such as SalticuSy capture 

 their prey by springing on it from a distance : others, such 

 as the common House-spider, Tegenaria, enixsi^ their prey 

 in funnel-like webs: the webs of others, sxxzh os Pholcus 

 are irregular in shape : while the webs of a large number 

 of Spiders, such as Epeira and Gasteracantha, have a 

 beautiful wheel-like symmetry. 



In the family of Spiders that spring upon their prey 



