143 



4 (5) Ventral glands in XIII-XIV; brain one and one half times 



longer than wide, posterior margin distinctly emarginate; 

 moderately developed clitellum on XII-XIII, incomplete on 

 ventral side rutilus 



5 (4) Ventral glands in III-V ; brain, slightly longer than v^ide, pos- 



terior margin angular and deeply emarginate ; clitellum thick 

 and conspicuous, completely surrounding XI-XTI agilis 



6 (i) Spermatheca with glands covering entire length of duct. 



7 (14) Spermatheca with distinct rosette of glands at ectal opening 



of duct. 



8 (9) Spermathecal ampidla large, rounded, and distinctly differ- 



entiated ; ventral glands in XIII-XVII, clitellum on 3^2 XI- 

 XIII ritteri 



9 (8) Spermathecal ampulla small and inconspicuous. 



10 (13) Clitellum on >< XI-XIV; ventral glands in XIV-XVII, all 



of uniform size. 



11 (12) Ampulla small and conical, constituting about one third of the 



whole spermatheca; testes consisting of 12 to 15 lobes 



merriami 



12 (11) Ampulla conical but larger, constituting approximately one half 



the length of spermatlieca ; testes with about 10 lobes 



incrviami. var. elongatus 



13 (10) Clitellum on K^ XI- y. XIV; ventral glands in XIV-XIX, 



small ones in III— X anmiJatns 



14 (7) Spermatheca with no rosette of glands at ectal opening of duct. 



15 (18) Setae of a bundle of approximately uniform size. 



16 (17) A'^entral glands in XIV-XVI, moderate in size and not divided 



into lobes franciscauus 



17 (16) \^entral glands in XIII-XIV, large, not divided into lobes. . . . 



franciscauus, var. nualaskm 



18 (15) Setae of a bundle not of uniform size; ventral glands in XIII— 



XV, large, posterior two divided into a number of lobes. . . . 

 franciscauus, var. borealis 



LUMBRICILLUS RUTILUS H. Sp. 



(PI. VIII, Fig. 13; PI. IX, Figs. 14-24) 



Definition. — Length, 15-19 mm. Diameter, 0.44-0.68 mm. 

 Somites, 41-49. Color, red w^ith slight tinge of yellow. Prostomium 

 rather short and rounded. Head pore on o/I. Dorsal pores absent. 

 Setae sigmoid; all of same size and approximately of same length; 

 in anterior ^ to % of body, 6-7 in lateral bundles, and 5-10 (usu- 

 ally S~7) '" ventral bundles; 2-4 in posterior part of body. Clitellum 

 on XII-XIII, interrupted on mid-ventral surface. Brain about one 

 and one-half times longer than wide; anterior margin concave, pos- 



