169 



Bay, Alaska), E. sa.vicola Eisen and B. citrinus Eisen (Lowe Inlet, 

 British Columbia), B. inarimis Moore (Bermuda Islands), and B. 

 albiclus Henle (Germany; N. American locality, Massachusetts, U. S. 

 A.). One new species, B. gilletteiisis, is described in the following 

 pages. 



Key to the Species oe Enchytr^us known to occur in 



North America 



1 (lo) Diverticula present on ampulla of spermatheca. 



2 (7) One diverticulum on ampulla of spermatheca. 



3 (6) Spermiducal funnel witli length not exceeding four times the 



diameter. 



4 (5) Peptonephridia present; brain with convex posterior margin; 



length, 20-25 mm kincaidi 



5 (4) Peptonephridia absent; posterior margin of brain with slight 



median concavity; length, about 10 mm iiiarintts 



6 (3) Spermiducal funnel very long and narrow, length exceeding 



four times the diameter; posterior margin of brain with deep 

 emargination ; extensive sperm sacs present; length, 15—20 

 mm saxicoia 



7 (2) Two diverticula on ampulla of spermatheca. 



8 (9) Posterior margin of brain concave; diverticula of spermatheca 



equal in size alaskce 



9 (8) Posterior margin of brain convex; diverticula of spermatheca 



unequal in size citrinus 



10 (i) No diverticula on ampulla of spermatheca. 



11 (12) Spermatheca not connecting with digestive tract, straight and 



more or less covered throughout its entire length with small 

 glandular cells; no distinct and enlarged ampuWa. .luodestus 



12 (11) Spermatheca connected with digestive tract. 



13 (16) Spermatheca short and stout, the duct being about the same 



length as ampulla ; length exceeding 10 mm. ; somites over 50. 



14 (15) Duct of spermatheca not set off distinctly from ampulla; con- 



nects with digestive tract at one side of ampulla and not at 



apex; large compact crown of glands at ectal opening 



nietlakatlensis 



15 (14) Duct of spermatheca distinctly set off from ampulla; connection 



with digestive tract apical ; ectal half of duct covered with 

 closely set pear-shaped gland cells alhidiis 



16 (13) Spermatheca long and slender, the duct being about four times 



as long as ampulla ; glands cover entire length of duct ; length, 

 2.5-4.5 mm. ; somites, 25-27 gillettensis 



