SPIDERS 165 



The remaining families such as the Theraphosidae, Dysderidae, 

 Oonopidae, Gnaphosidae and Clubionidae contain mostly short- 

 sighted nocturnal hunters that depend upon the sense of touch and 

 grapple with any suitable insect they come across in their wander- 

 ings. Harpactea hombergi, a small grey species common under bark, 

 holds its victims with its tarsal claws, while the large and formid- 

 able Dysdera crocota and D. erythrina, easily recognised by their 

 red cephalothorax and yellow abdomen, feed mostly upon woodlice 

 and lunge forward so quickly that few escape. Their chelicerae are 

 especially adapted for dealing with this prey; they are exceptionally 

 large and powerful, and by tilting the prosoma sideways one fang 



Fig. 35. Dysdera sp. eating a woodlouse. (After Bristowe, 1954.) 



is intruded beneath the woodlouse and the other above it. Scoto- 

 phaeus hlackwalli is a mouse-coloured house spider that often falls 

 into baths and sinks and then cannot climb out. Like many other 

 Gnaphosidae and Clubionidae, it relies upon its speed for the 

 capture of its prey, while the ferocious Drassodes lapidosus, fre- 

 quently found under bark and stones, immobilises its prey by 

 swathing it in bands of silk. 



Perhaps the most interesting method employed in the capture 

 of insects is that of the rare Scytodes thoracica. This slow-moving 

 yellow coloured species squirts poisonous gum from its jaws 

 whilst on the move after the manner of a cruiser tank spraying 



