Geophilus is a much longer animal than Lithobius, for its body may consist of from 80 to 180 rings. The species have no eyes. Several of them are common, especially in the south of England, and possess, as do many genera of the same family, the property of phosphorescence, whence have arisen the stories of ‘luminous earthworms’ current from time to time. _Geophilus crassipes_ is the form most frequently captured when displaying its light. It is from one inch to two inches long, of a reddish-orange colour, and somewhat worm-like in shape. Mr. Pocock, of the British Museum (Natural History), says: ‘The property of luminosity lies in an adhesive fluid secreted by glands which open upon the lower surface of the body, and the power of discharging or retaining the fluid appears to be entirely under the centipede’s control. The phenomenon is observable during the autumn months, from about the middle of September to the end of November, and although its significance is not clearly understood, it is generally believed to be connected with the pairing of the sexes[40].’ During a visit to the seaside it is well to look out for specimens of a marine Centipede, which is, apparently, not very common. It is said to occur ‘under stones and sea-weeds on the shore at or near Plymouth’; and in 1895 I had the good fortune to meet with one at Bexhill. This Centipede does not live in the sea, but will survive prolonged immersion in salt water. It is far too valuable for us to pick to pieces, so that, if we should have the good fortune to meet with one, we should carefully examine it, making what notes are necessary, and then pickle the specimen and send it to the British Museum, Cromwell Road, S.W. The tube should be labelled with the place and date of capture, and it should be stated on the label whether the animal was taken above or below high-water mark. The Common Millepede--often miscalled the wireworm--is readily distinguished by the absence of poison-claws, and its cylindrical worm-like appearance. De Geer, who of course adopted the Linnaean definition of ‘Insects,’ says of the Millepedes of the genus Julus, to which our Common Millepede (_Ju´lus terres´tris_) belongs: ‘They form, as it were, the last link of the chain which unites the class of Insects to that of Worms, for the body is elongated and cylindrical; and though they have a great number of feet, these are so short, that when these animals walk, they seem rather to glide along after the fashion of legless worms[41].’ [Illustration: FIG. 64.--The Common Millepede.]