TERRICOLA AND GEPHYREA. 379 



SUB-SECTION IV. 

 THE ORDER OF TERRICOLA OR EARTH-WORMS. 



THE Earth- worms or Lumbrieidse are so well known 

 that we must give them only a passing notice, although 

 they are very interesting in their structure, and exceed- 

 ingly interesting in their habits. 



The Earth-worms have no visible external organs of 

 respiration, but apparently respire by the whole surface 

 of their body. They eat dirt and thus secure the organic 

 matter which it contains. 



FIG. 513. 



Earth-worm Lunibricus terrestris, Linnceus. 



And, contrary to the popular notions, these animals, by 

 their burrowing and working over of the soil confer great 

 benefits upon the farmer and gardener. 



SUB-SECTION V. 

 THE ORDER OF GEPHYREA. 



THE name of this group is from the Gr. gephyra., a 

 bridge, and is given to certain marine worm-like forms 

 which are regarded as a sort of connecting link or bridge 

 between the Holothurians (Fig. 670.) and the Vermes. 



