THE VICTORIAN NATURALIST, 131 



Now to these light-abhorring animals, which Hve concealed 

 under logs and stones and beneath the dead bark of trees, and 

 venture forth from their hiding places, if at all, only at night or 

 under exceptional circumstances, it will be convenient to give a 

 distinct name indicative of their peculiar habitat, and though I ha.ve 

 carefully studied the Greek dictionary I can find no more suitable 

 term than " Cryptozoic^' or living hidden, which, though by no means 

 perfect, I think fairly expresses my meaning. By the cryptozoic 

 fauna, then, I mean all that assemblage of animals which is found 

 living habitually under logs and stones and under the rotten bark 

 of trees. I had thought of including under the term also bur- 

 rowing animals such as the mole and the earthworm, but decided 

 finally that it was better not to do so. The line must be drawn 

 somewhere, and if we draw it as I propose I think we shall 

 circumscribe a fairly distinct and definite group of animals. 



I must now say something about the cryptozoic fauna of Wal- 

 halla, and I will begin with the Land Planarians. The Planarians 

 form a very well characterized and distinct group of lowly 

 organized worms, of which the majority are inhabitants of salt or 

 fresh waters. It is probable that the comparatively few genera 

 which live on land are descendants of aquatic ancestors, and to 

 this fact is probably to be attributed their hatred of light and air 

 and their partiality to damp crevices under stones and dead wood. 

 The terrestrial forms are elongated, very soft bodied worms, 

 flattened on the lower surface, which is used for crawling on. 

 When lying still they coil themselves up, and when they begin to 

 crawl they stretch themselves out greatly, and the body becomes 

 correspondingly narrower. The anterior extremity of the animal 

 is narrow and horse-shoe shaped, and bears usually a large num- 

 ber of very minute eyes. When the animal is actively crawling 

 this anterior end of the body is raised up off the ground as though 

 the worm were trying to see its way, which is doubtless the case. 

 The size of the animal varies with the species, but averages some 

 three inches in length when crawling. The entire animal is covered 

 with an intensely sticky coating of sHme, which is left behind as a 

 trail when the worm crawls. One of these worms, which I captured 

 at Warburton, escaped from the bottle in which it was confined, 

 and for some time I thought it had gone for ever, but at last I 

 noticed a shiny track on the wall of the room, and following it up 

 found that the worm had squeezed through the crack between the 

 mantelshelf and the wall, and thence found its way on to the floor, 

 where I speedily recaptured it. 



In about the centre of the under surface of the body there is 

 always a very small round hole. This leads into a spacious cavity 

 within the body in which the animal keeps a large sucker neatly 

 folded up and packed away when not in use. When it wishes to 

 feed, however, it unpacks the sucker and puts it out through the 



