362 Mr. Newport on the Class Myriapoda, Order Chilopoda. 



a poison to them, and they usually die within a few hours. Their bite is 

 poisonous to small Articulata ; and I have little doubt that they inject a fluid 

 into the wound from the apex of the mandibles, and that a poison-gland is 

 contained in the base of these organs, as I have discovered in Scolopendra, 

 although I have not yet detected it in Lithobius. Degeer*, who was more 

 practically acquainted with the habits of Insects and Myriapoda than almost 

 any other naturalist of the last century, says, " J'ai vu qu'une mouche, qui 

 fut mordue par une de ces Scolopendres, mourut presque dans I'instant, ce qui 

 semble etre une marque que leur morsure est veniraeuse." But the effect of 

 the bite of Lithobius was not so marked on the worm, although I doubt not 

 that it was more rapid on the fly ; precisely as the bite of the larva of the 

 glow-worm, as I have often witnessed, almost instantaneously paralyses its 

 natural prey, the garden snail. Helix hortensis, which dies quickly from the 

 effects of repeated bites. 



Very little is at present known of the mode of development of the Litho- 

 biidce beyond the fact that their young acquire periodic additions of segments, 

 legs and eyes, like the lulidoe ; and also, as I have satisfactorily ascertained, 

 that they cast their tegument at distant periods of growth, and are capable of 

 reproducing lost parts, like the Crustacea and Arachnida. The Lithobiidce are 

 frequently found with one or more of the legs much smaller than the rest, 

 although with the same number of joints. These are limbs that have been 

 reproduced, perhaps even a second time, as I have elsewhere shownf. The 

 only instance I am acquainted with of the development of supernumerary 

 limbs in the Myriapoda exists in a specimen of L. Leachii in my own collection. 

 In this instance the anterior or prothoracic leg, on the right side, has the tibia 

 exceedingly short ; but the tarsus is enlarged, and not only gives attachment 

 to a metatarsus, formed of two joints and a claw, but also to another tibial 

 joint, from the middle of which a second biarticulated metatarsal joint is pro- 

 duced, and from its extremity also a third ; each joint having its complete 

 armature of spines and hairs. 



The generic characters of the Lithobiidce have been almost as imperfectly 

 studied as their natural history. The best characters of the family are the 



* M^moires pour I'Histoire des Insectes, torn. vii. p. 557. 

 t PhU. Trans. 1844, part ii. pp. 283 to 288. 



