ZooL.— Vot. II.] RISEN— OLIGOCHMTA. 179 



field is connected anteriorly with two deep pits in the pos- 

 terior margin of XVII. Somites XXI, XXII, XXIII are 

 occupied by two large ventral pear-shaped swellings, as 

 wide as the zone in XVII-XX. Each one of these pear- 

 shaped swellings occupies one and a half somites. There 

 are no other papillae. 



The clitellum appears ring-shaped and perfect, except for 

 a V-shaped ventral depression in XIII and XIV. The clitellar 

 somites are of even size and form and quite smooth. The 

 intersegmental grooves are perfect. 



Spej'maihecal Sexual SetcB and Glands. Setae ab in VIII 

 and IX are differentiated sexual setae. They are strongly 

 sculptured in about the same way as those of Diplocardia 

 Udei, but the anterior part of the ridges are drawn out into 

 short spines. 



The set£e are accompanied by glandular structures in the 

 body-wall, as far as I can see exactly like those in Diflo- 

 cardia Udei, only not quite so numerous. They all open 

 into a common globular chamber, there being no side 

 chambers as in D. Udei. 



Internal Characters. 



Septa. — The enlargement of the septa is principally 

 dorsal. This refers especially to the septa separating 

 VII/VIII, VIII/IX, in which the dorsal part is two or three 

 times wider than the ventral part. 



Septal and Pharyngeal Glands. — The suprapharyngeal 

 glands are well developed. There appear to be at least 

 seven dorsal lobes. There are three pairs of very minute 

 septal glands in VI, VII and VIII, situated close to the 

 intestine and suspended by muscular strands. The one in 



VIII is the largest, and is at the widest part as wide as the 

 wall of the intestine. Those in VI and VII are much 

 thinner and one to three cells thick. A very interesting 

 fact is that throughout the intestine in somites VII, VIII and 



IX are seen isolated dark-staining streaks, which upon 

 examination are found to consist of glandular cells, exactly 



