1 12 Invertebrata. 



earth and web united together and hinged by a silken 

 hinge. These trap-door spiders are found along the 

 shores of the Mediterranean, in California and Ja- 

 maica. Some spin little cocoons or silken cases for 

 their eggs, which theycarry about with them, and -in 

 protecting which they exhibit great activity. The 

 maxillary 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, ending in a tail-like portion. The maxil- 

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

 ing takes place by pulmonary sacs like those of 

 spiders. The last joint of the abdomen bears in 

 scorpions a sharp spine at its end, perforated by the 

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

 wounds. A little creature named Chelifer, some- 

 what allied to scorpions, but with no tail nor sting, is 

 often found in old books. 



CHAPTER XXI. 



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 three 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 



