112 Invertebrate*. 



earth and web united together and hinged by a silken 

 hinge. These trap-door spiders are found along the 

 shores of the Mediterranean, California and Jamaica. 

 Some spin little cocoons or silken cases for their eggs, 

 which they carry about with them, and in protecting 

 which they exhibit great activity. The mandibular 

 palps are never pincer-bearing or used for walking 

 although sometimes long. 



Scorpions. The scorpions and their allies are 

 characterised by the possession of a long segmented 

 abdomen, followed by a post-abdomen. The mandi- 

 bular palps form pincers, like crabs' claws, and breath- 

 ing takes place by pulmonary sacs like those of 

 spiders. The last joint of the post-abdomen bears 

 in scorpions a sharp claw at its end, perforated by 

 the duct of a poison-gland, and thereby it inflicts 

 painful wounds. A little creature named Chelifer, 

 somewhat allied to scorpions, but with no post-abdo- 

 men nor sting, is often found in old books. 



CHAPTER XXL 



CENTIPEDES. GALLYWORMS. 



CLASS III. Myriopoda. This comparatively small 

 class includes the centipedes, whose long jointed bodies 

 are to be seen rapidly crawling under old rotten sticks 

 and stones and shunning the light. In this country 

 they rarely exceed two inches in length, but in the 

 tropics they reach from six to twelve inches or even 

 more, and their bites are poisonous and severe. One 



