378 Proceedings of the Royal Physical Society. 



Plateau had stated, I have dissected numerous Chilopods, 

 and as in some ways my results are different from his, I 

 have thought I may as well record them. 



Lithohius. — Of this genus I have dissected three species, 

 L. grossipes, L. variegatiis, and L. forficatus. Of the first two 

 I have only dissected a few examples, but of L. forficatus I 

 have examined over a hundred specimens, and as I find that 

 there is little difference in the digestive organs of the three 

 species, I shall describe them as I find them in L. forfi- 

 catus. 



Lithohius appears to feed principally on diptera, at least in 

 captivity. Plateau found this to be the case, and in the 

 numerous experiments which I have made I have quite 

 failed to get captive Lithohii to take any other food than 

 flies, gnats, and some small neuroptera (Sialis, etc.) and 

 trichoptera. It has been stated, however, that they devour 

 worms, and that in the case of a comparatively large worm 

 two Lithohii will attack it at once. 



The alimentary canal is easily seen to fall into three 

 divisions, a short oesophagus, a large stomach occupying 

 the greater part of the interior of the body, and a short 

 intestine. Besides these three parts we may consider 

 also the two large glands situated in the fore part of the 

 body, and the two malpighian tubes which open into the 

 alimentary canal at the juncture of the stomach and 

 intestine. 



The oesophagus is short and relatively broad. When 

 viewed in its natural position it is seen to be some- 

 what larger at its posterior extremity than in the anterior 

 portion. It is generally of deep violet colour. Plateau 

 mentions his having found it white in some Lithohius for- 

 ficatus, I have not done so in this species, but in all the 

 L. grossipes which I have dissected it was of a pale yellow, 

 and in L. variegatus of a deeper purple colour than I have 

 found it in L. forficatus. 



It is formed of an outer muscular layer, an epithelium 

 formed of cells of colourless protoplasm with well-developed 

 nuclei, and a thin transparent lining, which, towards the 

 posterior extremity, is studded with minute chitinous spines, 



