ENCHYTR^EID^E 121 



Ovaries extend as far back as XV and XVI. 



The nephridia are long and the anteseptal part is nearly equal in 

 length to the postseptal part. The anteseptal is divided transversely 

 into two nearly equal, globular parts. The nephrostome is small. 

 The postseptal part is long and rectangular, with crenate edge. The 

 duct in the anteseptal is spirally wound. Only the part nearest the 

 nephrostome is ciliated. 



Lymphocytes. The larger kind is round, transparent, and its 

 nucleus stains blue. The smaller kind is also round and transparent, 

 but its nucleus stains reddish with eosin-thionin. 



Setae. The setae in each bundle are frequently of odd numbers. 

 Thus one bundle may have on one side three setae and on the other 

 only one, or there may be three on one side and only two on the 

 other. The central setae are always the smallest. When setae are 

 wanting on one side it is always the small setae which are missing. 



Chylus cells. In the three somites next posterior to the clitellum, 

 the intestine possesses numerous chylus cells, separated by common 

 ciliated epithelial cells. These chylus cells are long and comparatively 

 narrow, each containing a single duct. The duct is perpendicular to 

 the base of the cell, except at the very base, where the duct is bent, 

 running parallel with the basal membrane. The duct is surrounded 

 by a thin layer of granular dense cytoplasm. The interior of the 

 duct is ciliated along its upper course. 



BIBLIOGRAPHY. 

 Beddard, F. E. 



1895 A Monograph of the Order Oligochaeta, pp. 769, 5 pis. London. 1895. 

 Bretscher, K. 



1899 Beitrag zur Kenntnis der Oligochaetenfauna der Schweitz. Aus dem 

 zoologischen und vergleichend-anatomischen Laboratorium beider 

 Hochschulen in Zurich. Inaugural-Dissertation. Geneve, W. KUndig 

 Fils. 



1900 Mitteilungen liber die Oligochatenfauna der Schweiz. Revue Suisse de 

 Zool., vni, pp. 1-44. 1900. 



1900 SUdschweizerische OHgochiiten. Revue Suisse de Zool., vm, pp. 435- 

 458. 1900. 



1901 Beobachtungen liber Oligochaten der Schweiz. Revue Suisse de Zool., 

 ix, pp. 189-223. 1901. 



Biaen, Gustav. 



1879 On the Oligochaeta collected during the Swedish Expeditions to the 

 Arctic Regions in the years 1870, 1875, 1876. Kong. Sv. Vet. Akad. 

 Handl., Bd. 15, No. 7, 1879. 



