MR. A. MAYFIELD ON NORFOLK EARTHWORMS. 
575 
may be identified, are, (1) Their colour and size ; (2) The girdle or 
ditellum, an organ possessed by adult specimens only, and which 
is an organ of reproduction ; (3) The two segments which form 
the head. Of these two segments (which are not counted in 
determining the position of the girdle), the first, the prostomium, 
contains the mouth, and is inserted in the second, the peristonnum, 
which embraces it, either totally or partially. 
The British Earthworms are included in the four following 
genera : — 
(«) Lumuricus. The prostomium inserted so as to divide the 
peristomium into two parts. The seta-, or bristles, arranged in 
four close pairs upon eacli segment behind the peristomium. 
Surface, iridescent. Mucous, colourless. 
( It ) Allolohoi’HORa. Prostomium only partially inserted in the 
peristomium. Bristles arranged in four pail's, sometimes separated. 
Some species exude a yellow and foetid fluid when touched. 
Surface not iridescent. 
(c) Dendrobiena. The insertion of the prostomium irregular. 
The bristles have a tendency to be arranged in eight rows along 
the body of the worm. Small worms inhabiting rotten wood and 
other vegetable matter. 
(r/) Allurus. Segments behind the girdle four-sided, having a 
pair of bristles at each angle. 
1. Lumbiuous terrestris, Linn. The Common Worm, Lob- 
worm or Lew-worm. Girdle upon segments 32 — 37. Length, 
about 5 inches. Colour, greyish-white, with a pink or brown tint 
in front of the girdle. This worm is not so common as has 
generally been supposed ; in fact, it is said that in some parts of 
England it is rarely seen. It has been confused with AHolobophora 
luwja, the Bluenose, which equals it in size. However, it may be 
easily distinguished from tins latter species by its lighter colour, 
and by the position of the girdle, which in A. lonyu occupies 
segments 28 — 35. The Common Earthworm is plentiful about 
.Norwich, and is found in gardens and fields. 
2. L. rubellus, liollin. The Ked Worm. Girdle on segments 
27 — 32. Colour, red. Length, about 3 inches. This species is 
rather uncommon in jN'orfolk. It frequents meadows and damp 
hedgebanks. I have found specimens at Earlham, Hellesdon, and 
Old Lakenham. 
