140 LUMBRLCUS. 



e. LUMBRICUS TERES. Plate XVII., Figs. 10, 11, 12. 



Length, eighteen lines ; thickness, nearly half a line ; body round, 

 tapering towards each extremity, faintly indented by numerous annula- 

 tions, with a row of bristles at intervals down each side. Plate XVII. 

 fig. 10 ; an outline of the head enlarged is seen fig. 11. The mouth seems 

 below, and the termination of the intestinal canal in the centre of the 

 posterior extremity. Under the microscope a red vessel is discovered 

 running down the middle of the body ; and the interanea, which are of 

 peculiar formation, are finely variegated when full. Colour various 

 brownish shades ; the extremities light. This animal swims by contor- 

 tions in the water. One committed to a watch-glass proved so restless 

 as to render observation inconvenient ; but another being introduced, 

 both were perfectly quiet. 



It forms a tube of muddy particles, which is permanently occupied. 



The Lumbricus teres inhabits a small pond in the city of Edinburgh, 

 in Heriot Row gardens. 



PLATE XVII. 



FIG. 10. Lumbricus teres. 



11. Outline of the head, enlarged. 



12. Section of the body shewing the formation of the interanea, enlarged. 



/. LUMBRICUS HIRSUTUS. Plate XVII., Figs. 13, 14, 15, 16. 



Length about fifteen lines ; thickness, half a line or less ; body 

 cylindrical, composed of a number of segments, with lateral rows of 

 bristles, a pencil being situate on each side of each segment, all of which 

 are very conspicuous on the upper segments. The whole body is covered, 

 besides, with short hairs, rather thinly set. Colour of the anterior portion 

 whitish, of the remainder dull red or umber. 



A specimen occurred in February, among some collections, on the 

 coast of Fife. It was lost accidentally immediately after delineation. 



