THE EARTH-WORM. 



707 



Sometimes this beautiful annelid attains a considerable size, reaching the length of 

 five or even six inches. Generally, however, from three to four inches is the measure- 

 ment. It is a slow-going, but very voracious creature, feeding even upon its own kind 

 and using its powerful proboscis as a means of capture. 



In some species of this genus, the spines which edge the body are most marvellously 

 formed. They are set upon projecting footstalks, and when not required for use can be 

 drawn back into the body. Their shape, however, would seem to render such a pro- 

 ceeding dangerous, inasmuch as they are formed just like the many-barbed spears used 

 by certain savage tribes. In the Aphrodite hispida, for example, they are just like 

 doubly-barbed harpoons, and would wound the soft tissues of the body most severely 

 when withdrawn. In order, therefore, to prevent this result, each spine is furnished with 

 a sheath composed of two blades, which close upon the barbs when the weapon is with- 

 drawn, and open again to allow its exit when it is protruded. 



THE second species represented in the above illustration is easily distinguished from 

 the preceding creature by the peculiar structure of the back, which is devoid of the 

 felt-like substance, and the scales are consequently bare. 



CH/ETOPTERUS. Chatoptenis pergamentaceus. 



ON account of the singular structure of the CH^TOPTERUS, it has been placed in a 

 family by itself, of which it constitutes the sole genus. 



This remarkable worm is one of the tube-builders, and makes a dwelling of a tough 

 parchment-like consistency, measuring eight or ten inches in length. It is found in the 

 seas about the Antilles. In this curious being there is no distinct head, and no vestige 

 of maxillae, but the proboscis is furnished with a lip, to which -are attached two small 

 tentacles. " Then comes a disk with nine pairs of feet, then a pair of long silky 

 bundles, like two wings. The gills, in the form of laminae, are attached rather below 

 than above, and predominate along the middle of the body." 



THE next family, of which the common EARTH-WORM is a very familiar example, is 

 distinguished by the ringed body without any gills or feet, but with bristles arranged 

 upon the rings for the purpose of progression. 



In the well-known Earth-worm, the bristles are short and very stiff, and are eight in 

 number on each ring, two pairs being placed on each side ; so that, in fact, there are 

 eight longitudinal rows of bristles on the body, four on the sides, and four below, which 

 enable the creature to take a firm hold of the ground as it proceeds. 



