CH. I] EARTHWORMS AND LEECHES 39 



S. vejdovskyi Benham. Orange-red. Segments 2 to 4 annulate. 

 Setae prong-forked, upper shorter than lower prong. Length 

 about 25 mm. On roots of water plants. Cherwell, 

 Thames, etc. 



Family ENCHYTRJEID.E. Sperrnathecal apertures in furrow between 

 4th and 5th segments, rarely between 3rd and 4th also. Setae 

 styliform or hooked, not forked, straight or slightly sigmoid, 

 without distinct node ; generally in fan-like bundles of 3 to 12, 

 rarely fewer : arranged in 4 bundles per segment in all British 

 genera. Head pore present. Male apertures 1 pair, in 12th ; 

 female 1 pair, in 13th. Testes in llth, on septum between 

 10th and llth segments ; ovaries in 12th on that between llth 

 and 12th. 



genus Manonina Mchlsn. Setae sigmoid. Head pore small 

 between prostomium and 1st segment : no dorsal pores. 

 Dorsal blood vessel starts from mid-gut plexus behind 

 clitellum ; no hearts. Testes moderate, vasa deferentia 

 long. Blood yellow-red. (Esophagus without pouches in 

 6th segment ; not sharply marked off from mid -gut. 

 M. crassa (Clap.). Pale red. Setae 3 or 4, rarely 2 or 5 per group. 

 Lymph corpuscles of two forms. Penis small, sub-spherical. 

 Total segments 40 to 48. Length about 15mm. Seashore. 

 Hebrides (Skye). 

 M. ebudensis (Clap.). Yellowish. Segments about 47. Length 



12 mm. Seashore. Hebrides (Skye). 

 genus Lumbricillus Orst. Characters as in Marionina, except 



testes composed of numerous pyriform lobes. 

 L. verrucosus (Clap.). Keddish. Setae 3 to 5 per group. Total 

 segments 45 to 50. Length 10 to 12 mm. : thickness 0'5mm. 

 Seashore. Hebrides (Skye). 



genus Enchytrceus Henle, em. Mchlsn. Setae straight, of equal 

 length in same group. Head pore, dorsal pores, blood vessel, 

 hearts, and oesophagus as in Marionina. Blood colourless. 

 Spermathecae communicate with gut. 



E. argenteus Mchlsn. Silvery white. Lymph corpuscles by trans- 

 mitted light nearly black. Total segments 23 to 30. Length 



