160 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 52. 



19 (20) (21) Clitellum, 27 or 28-34 or 35; tubercula pubertatis, 31 and 33 or 31-33. 



H. {A.) caliginosus or var. 



20 (19) (21) Clitellum, 27 or 28-35; tuljercula pubertatis, 32-34 E. (A.) longus. 



21 (19) (20) Clitellum, 29-37; tubercula pubertatis on 31, 33, and 35.//. (A.) chloroticus. 



22 (18) (25) Three pairs of sperm sacs in 9, 11, and 12; spermathecae present; setae of 

 North American species mdely paired or separate Subgenus Dendrobaena . 23. 



23 (24) Clitellum, 27, 28, or 29-33 or 34; tubercula pubertatis. 31-33. .//. (D.) octaedrus. 



24 (23) Clitellum, 25 or 26-31 or 32 ; tubercula pubertatis, 28-30 ..II.{D.) suhruhicundm. 



25 (18) (22) Two pairs of sperm sacs in 11 and 12; spermathecae al)sent (sometimes 

 imperfectly developed in H. tenuis) Subgenus Bimastus 26. 



2G (39) Setae more or less closely paired 27. 



27 (28) (35) Clitellum, 23-28; large chamber at end of sperm duct. . .//. {B.) palustris. 



28 (27) (35) Clitellum, otherwise but including less than ten somites 29. 



29 (32) Anterior margin of clitellum, anterior to 23 30. 



30 (31) Clitellum on 22-29; ab equal toed H. (B.) tumidus. 



31 (30) Clitellum, beginning at 20-22; ab greater than cd 



H. (B.) gieseleri and var. hempeli. 



32 (29) Anterior margin of clitellum on 24 or 25 33. 



33 (34) Clitellum, 24-30 H. (B.) parvus. 



34 (33) Clitellum, 24 or 25-31 H. (B.) beddardi. 



35 (27) (28) Clitellum including 10 somites or more 36. 



36 (37) (38) Clitellum, 23-32 or 24-33 E. {B.) longidnctus. 



37 (36) (38) Clitellum, f 25-35 E. (B.) welchi. 



38 (36) (37) Clitellum, 27-37 E. (B.) zeteki. 



39(26) Setae, widely paired; clitellum, 26-31 or 32 E. (B.) tenuis. 



40 (2) Spermaries and spermiducal funnels inclosed in sperm vesicles ; clitellum, 30-35; 

 tubercula pubertatis, 31-34; setae separate or widely paired . .Octolasium lacteum. 



41 (1) Prostomium completely divides the peristomium, tanylobic; spermaries and 

 spermiducal funnels inclosed in sperm vesicles; sperm sacs in 9, 11, and 12. 



Lumbricus. 42. 



42 (43) (44) Clitellum, 26 or 27-32; tubercula pubertatis 28-31 L.rubellus. 



43 (42) (44) Clitellum, 28-33; tubercula pubertatis, 29-32 L. castaneua. 



44 (42) (43) Clitellum, 31 or 32-37; tubercula pubertatis, 33-36 L. terrestris. 



Lumbricus festivus (Savigny), clitellum, 34-39, has been reported in Canada by 



Stafford (1902). 



Family LUMBRICIDAE. 



Earthworms of this family have but eight setae to each somite. 

 The anterior border of the clitellum is posterior to the spermiducal 

 pores which in the great majority of species are on somite 15 but 

 in a few, are one to three somites further anterior. A calcif erous gland 

 is present in the region of the gonads and a gizzard at the anterior 

 end of the intestine. There are no typical prostate glands extending 

 freely into the coelomic cavity. As in the great majority of earth- 

 worms, the spermaries and spermiducal funnels are in 10 and 11 

 and the ovaries in 13 and oviducal pores in 14. 



A satisfactory grouping of the species of this family into genera 

 and subgenera has proven to be extremely difficult. Michaelsen 

 has recently (1910) discussed these difficulties and has reduced 

 the number of genera to three — Helodrilus, Octolasium, and Lum- 

 bricus. Helodrilus includes the great majority of the species of the 



