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Art. LXI. — Notes on Myriapoda. By Feancis Walker, Esq. 



Genus. — Lithobius. 

 When their antennae require brushing or cleaning, they bend those organs, which 

 have great flexibility and rapidity of movement, under the mandibles, which are at the 

 same time extended, and thus holding them down, they let them gradually reassume 

 their former position, brushing eveiy successive joint with the palpi, which are then in 

 active motion. When touched or irritated they erect their four hindmost legs in an 

 attitude of defence, as the Staphylinites raise their tails. Whilst very young, and 

 little more than a line in length, the body is altogether white and transparent, and has 

 seven legs on either side, and about ten segments besides the head, and the antennse 

 have but very few joints, compared with those organs in the mature creature. 



Lith. Icevilabrum. Its body is sometimes quite soft, dull, pale, and tinged with 

 green, this is probably caused by its having recently changed its skin. The labium 

 is like the mandibles of many insects, it forms two distinct parts, which are stout, 

 square, united behind, and in front armed with six minute teeth of equal size, it is 

 sometimes called the exterior labium ; on either side of it is a large, long, hooked and 

 pointed jaw, used by the insect to seize its prey, and composed of five joints, the ba- 

 sal joint is large and long, the second, third and fourth are short and transverse, the 

 fifth joint is long, slender, black, hooked, smooth, shining, and ending in a point. — 

 These jaws extend along and beyond the sides of the head towards the base of the an- 

 tennae, thus the head seems broader than it really is. Desvoidy says that this part 

 corresponds with the third locomotive vertebra of Crustacea, and with the fore legs of 

 insects. In front of the head beneath is a small part, in shape like a short broad cone, 

 and set with bristles in front; this is the labrum or the labial vertebra of Desvoidy. 

 Behind this are the mandibles (or the maxillary vertebi'a of Desvoidy), which are small, 

 near together, and armed with little teeth. Next comes the inferior labium, which is 

 not very distinct ; it bears two palpi, and according to Desvoidy represents the first 

 locomotive vertebra of Crustacea and the maxillae of insects. Then follows another 

 segment, bearing well-developed three-jointed palpi ; and immediately behind it is the 

 exterior labium before described. On looking at the upper surface or notum of the 

 head, we see that it is composed of two segments, one comprising the greater part of 

 the surface, and having the eyes seated on either side of its front, is called by Desvoi- 

 dy the optic vertebra. In front of this, and just over against the mouth, is a narrower 

 segment, from which arise the antennas ; it is the olfactory vertebra of Desvoidy. The 

 antennae of this species have 30, 36, 37 or 40 joints, each successive joint being gene- 

 rally shorter than the preceding one ; the horny external substance is transparent, and 

 allows the internal nerves to be distinctly visible. Beneath the basal joint of each of 

 the eight or ten hindmost legs is a long oval concavity, armed with straight, parallel, 

 transverse ridges. The sexual parts are situate beneath the body, at the tail. The 

 dorsal plates are easily removed, and allow the internal canal to be seen. When held 

 it expresses great impatience, often opens its jaws, and applies their tips to each other 

 or to the tips of its palpi. Sometimes the auteuna have only 30 joints, and are more 

 obtuse at the tips. One of the penultimate legs being separated from the body vibra- 

 ted rapidly for a while, as if in the act of running ; however, the basal joint continued 

 motionless, and on being pressed, the contraction of the muscle caused the rest of the 

 leg to move as if the creature was walking, and the quickness of the motion corre- 

 sponded with the weight and suddenness of the pressure, and vibration sometimes en- 



