ZooL.— Vol. II.] EISEN—OLIGOCHMTA. I49 



The sacs with genial setce are very large, about as long 

 as three somites. The two sacs at each pore are joined 

 along their entire length; they consist of a larger sac-like 

 part which encloses the setae, and a shorter, narrower, and 

 tubular part, serving as a duct for the guidance of the seta 

 when it is projected. This duct is about one-third as long 

 as the main seta-sac, towards which it is sharply bent or 

 even closely folded. The two ducts of the respective setae 

 are closely joined, but not fused, and remain thus to the 

 very pore. The setae are of different forms. The longer 

 is a little more curved, and its apex, which is much nar- 

 rower, is bent towards the main part like a fish-hook. The 

 shorter seta is only a trifle shorter. It is less curved and 

 the tip is narrower and only slightly bent. Both setse are 

 smooth and have a small knob at the apex. The knob is not 

 quite smooth, being furnished with a few depressions and 

 elevations. 



The common setce are strictly paired, and measured with 

 a micromillimeter scale give the following comparative 

 values: — 



rt'-«=iio; a—b=i2', b—c^^O; c-d=io. 



Notiodrilus cristalifer, sp. nov. 



Plate XIV, Figs. 160-162. 



Definition. — Length 20 mm., width i mm. The anterior seven somites 

 smoother than those posterior. The genital zone is sunk as in Benhaniia. 

 The prostates in XVII and XIX open on prominent papillae. Setae strictly 

 and closely paired, all ventral. Penial setse slender, not ornamented. Neph- 

 ropores in front of setse d. Diverticles of the intestine in VII, VIII, IX. 

 Sacculated intestine in XII; gizzard in V. Spermathecae in VIII and IX. 

 Testes in X and XI. Racemose sperm-sacs in XII, very minute and ventral. 

 Plain sperm-sacs in IX. Sperm-funnels in X, XI; sperm-ducts not fused 

 until the male pore. Prostates confined to their own somites. Megane- 

 phridia, with numerous lime crystals. No typhlosole. Septal formula: — 



V/VI, VI/VII, VII/VIII, VIII/IX, IX/X, X/XI, XI/XII, XII/XIII, 



XIII/XIV. 



Habitat. — Tactic, near Coban, in Guatemala. One 

 specimen, July 4, 1882. 



