ZooL.— Vol. II.] RISEN— OLIGOCH^TA. 183 



greater than half the periphery. In VIII, IX and X, «-«=! i^ a-b. Penial 

 setae present, ornamented. Spermathecal setae differentiated in VIII-X, 

 highly ornamented, accompanied by glands in the body-wall. Clitellum dor- 

 sally XIII->^ XVIII, ventrally XIII-% XXI. Genital zone a narrow, deep, 

 rectangular depression, deeper than in any of the other species, surrounded 

 by a thick, elevated ridge. Tubercula pubertatis in XIX-XXI, a pair of papillae 

 in XVIII. Most anterior septum II I/I V. Oesophagus, no dilations containing 

 calcic concretions. Gizzards in V and VI. Sacculated intestine commences in 

 XVII. Dorsal vessel single, thickly covered with chloragogen cells. Hearts 

 in X-XII, with chloragogen cells. Meganephridia, no coelomic mantle. 

 Testes in X and XL Sperm-funnels in X and XI. Sperm-sacs, one preseptal 

 in IX, one postseptal in XII, both racemose. Oviducts small. Prostates 

 very short and thick, occupying two somites each. Spermathecas with a 

 diverticle hidden in the wall of the spermathecae, not perceptible except in 

 sections. Anterior spermathecae largest. , 

 Septal formula: — 



VI/VII, VII/VIII, VIII/IX, TX/X, X/XI, XI/XII. 



Habitat. — Raleigh, North Carolina. Collected by Messrs. 

 Brimley. 



This species comes nearest to D. Eiseni and D. rifaria^ 

 without exactly being intermediate between the two. From 

 D. Eiseni it differs in the position of the spermathecal 

 pores and in the number of somites containing sexually 

 differentiated spermathecal set«, there being two such 

 somites in the former and three in the latter species. There 

 is also a pronounced difference in the genital zone, which in 

 D. Udei \s very deep, with straight foss^. The species is 

 smaller than D. ri-paria, its color is much lighter generally, 

 being without pigment, and it possesses the sexual sperm- 

 athecal set£e which are lacking in D. rifaria. With those 

 species possessing three pairs of spermathecse D. Udei need 

 not be confounded. 



Detailed Description. 



Somites. — (figs. 145, 146.) The anterior somites in- 

 crease in size towards the clitellum, with the exception of 

 somites VIII, IX and X, which are much larger than the 

 other somites. These somites also contain the genital setae 

 described elsewhere. Those somites anterior to VIII are 

 all distinctly 3-ringed. Somites VIII, IX, X are perfectly 



(7) December 21, 1899. 



