ZooL— Vol. II.] RISEN— OLIGOCH^TA. 191 



in XXI. No. 2, One pair of papillae in XVII, one pair in 

 XX similarly situated. Besides there is one pair of papillae 

 in the posterior part of XIV, in line with the papillae of the 

 zone and of the same size or slightly larger. These two 

 papillae are situated on an elevated zone, or, in other words, 

 are surrounded by an elevated ridge which is closed in 

 front but open behind; it extends to the center of XV. 

 No. 3 is similar to No. 2 but has no papillae in XIV. In 

 the three specimens the papillce in XVII are larger than 

 the posterior papillee. 



The depressed zone is not of uniform depth in the three 

 somites, being much deeper at the anterior and posterior 

 ends. In the part occupied by somite XIX the zone is 

 hardly deeper than the main part of the somite, while in 

 XVIII and XX-^ XXI the zone is deeper at the end and 

 appears like two separate cavities, separated by a central bar 

 in XIX. There are tubercula pubertatis swellings in XIV 

 to XVII, but with no decided external characteristics. 



Diplocardia singularis Ude. 



Geodrilus singularis Ude, Zeit. f. wiss. Zool. Bd. LVII, 1894, p. 69. 



Definition. — Color dark brown. Size 65 mm. by 3 mm. Prostomium 

 divides somite I about one-half. Dorsal pores, most anterior one VII/VIII. 

 Spermiducal pores in XIX. Spermathecal pores, three pairs in VI/VII, 

 VII/VIII, VIII/IX. Prostate pores in XVIII and XX. Oviducal pore in 

 XIV, interior to setae a, surrounded by a glandular ridge. Setae, ventral, 

 lateral; d-d greater than half the periphery; a-a larger than b-c\ c-d some- 

 what larger than a-b; a-b about one-half as large as b-c\ I. i. shorter than v. i. ; 

 a-b half as long as /. i., and three times shorter than v. i. ; faintly ornamented at 

 apex. No setae a-b in XIX. Penial setae three times as long as the ordinary 

 setae, curved, not ornamented. Spermathecal setae not differentiated. Clitel- 

 lum, ring-like, XIII->^ XVII, saddle-shaped, y^ XVII-XVIII. Genital zone, 

 no rectangular field, two lunate grooves on V^ XVIII->^ XX, convexity to- 

 wards ventral median line. One pair papillae in XVII. One pair in XX. 

 Sometimes with a deep oval zone in XVI I->^ XXI (Smith's specimens). 

 CEsophagus strongly twisted, bead-like in X-XIII, narrower in XIV-XVI, no 

 calciferous folds. Gizzards in V and VI. Sacculated intestine commences in 

 XVII. Dorsal vessel single. Hearts, three pairs in X-XI I; in VI-IX narrow 

 vessels. Meganephridia, first pair, in II, small; pores ventral to setae d. 

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



