42 The Irish Naturalist. 



When found in lawns and meadows they are addicted to burrowing and 

 making large worm-casts on the surface of the soil. The solitary British 

 species is widely distributed. 



Group II. Disjuncta. 



In this group the most striking feature is to be found in the disposition 

 of the setae. As in the genus DendrohcBna, they form eight more or less 

 equi-distant rows. The British worms resemble Luinbricus in the 

 arrangement of the band (tuhercula pubertatis) on the ventral sides of the 

 girdle, but differ from that genus in the shape of the lip-insertion. 

 The body is cylindrical in front, and somewhat octangular behind, 

 owing to the arrangement of the setae. The male pores are on papillae 

 on the fifteenth segment, and Rosa remarks that " I receptacula seminis 

 sono in direzione della 3a setola."^ A small quantity of yellow fluid is 

 exuded from the posterior or anal extremity when the worm is irritated, 

 and the smell of garlic or some similar vegetable seems to pertain to the 

 animals, as is the case with some of our univalves. They are not averse 

 to poor, heavy soil in England, being most frequently found in ploughed 

 land which is rough, uncultivated, and cold. 



Group III. lYIucida. 

 Worms of medium size, exactly halfway between the true earth-worms 

 and the tree-worms (Lumhricus and Dendrohcena), form the third natural 

 group. They do not resemble either genus, however, in any other 

 particular. The colour is very variable, and ranges from a delicate 

 fleshy tint, through dull clay colour, to dirty green or yellow. The 

 setae are in close couples, and the worms are cylindrical throughout. 

 The first dorsal pore is usually about the four-fifth or five-sixth inter- 

 segment. All exude mucus, which in some cases is thick, leaving a 

 granular sediment, and disagreeable. They are not favourites with the 

 angler and do not as a rule frequent rich soil. They are found under 

 stones, in woods, or on the margins of ponds and ditches, and sometimes 

 in arable or pasture land, especially in localities which are too poor for 

 the more epicurean Luinbricus. As they are not usually found lying 

 half exposed from their burrows, the hinder part is not flattened, this 

 being a device for gripping the burrow. These form Rosa's second group. 



Group IV. Virgata. 



Under this heading I include the species which constitute the first group 

 in Rosa's classification. My own system is intended to show the con- 

 necting links between the genus Lumbricus on the one hand and the 

 genus Dcndroboena on the other ; and this is done in more ways than one. 

 There is a beautiful gradation to be observed in size, colour, shape, 

 arrangement, and disposition of parts, habits, and habitats, and the like, 

 between the two extreme points, when studied systematically, as here 

 presented. In the present group we find worms of which the principal 

 types are banded. They exude coloured fluid, their setae are wider apart 

 than in the foregoing, and "I receptacula seminis si aprono lantano delle 



. * " The spermathecae open in the direction of the 3rd row of setae " 

 (counting from below upwards). 



