..304 ' Jean Shannon •' 



The segments themselves are quite distinctly marked, especially 

 in the spirit specimens. There is a distinct median furrow around 

 -each segment, and towards the ajiterior end of the worm two 

 smaller furrows may generally be found, one on either side of the 

 main furrow. 



The prostomium is normally very nearly completely dove-tailed 

 into the peristominum. 



The openings to the exterior of the dorsal pores and of the repro- 

 ductive organs are mostly quite distinct, and can be seen with 

 the naked eye. 



On the dorsal surface the only openings that occur are the dorsal 

 j)ores. These are situated between the successive segments in the 

 median line, the first being between segments four and five. 



On the ventral surface the most conspicuous openings are those 

 of the vasa deferentia, on the eighteenth -segment. Each is sur- 

 rounded by two swollen somewhat semi-circular lips, is situated 

 iiway from the median line between the third and fourth pairs of 

 setae, and is not included in the clitellar region. (Plate XXVIII. 

 Fig. 1. (?) (Plate XXYIl. Fig. 1. ^). 



On the fourteenth segment ventrally is a single median raised 

 oval area, and in the, centre of this is the opening of the common 

 duct formed by the union of the right and left oviducts. (Plates 

 XXVIl and XXVII., Fig. 1 ^). 



Between segments six and seven, seven and eight, and eight 

 and nine, are the three pairs of spermathecal pores, opening ven- 

 trally. It is very difficult to decide whether they open in line 

 with, the fourth or the fifth seta. 



In one fresh specimen that I examined there seemed to be an 

 indication of two smaller openings, on either side of the main 

 pore. Subsequent dissection showed the presence of accessory glands 

 in this region in all instances. 



Besides these more conspicuous openings there are certain small 

 glands associated wdth the spermiducal gland, and communicating 

 with the exterior on the ventral surface between segments sixteen 

 and seventeen, nineteen and twenty, twenty and twenty-one, and 

 twenty-one and twenty-two. 



Internal Ar^atomy. 



Alimentary Caval. — The living Avorm has very marked power of 

 evaginating the whole crop to the extent very often of one-quarter 

 ■of an inch. Upon opening up the worm one finds that the front 



