168 Trmisactions. — Zoology. 



very much wider (astero-posteriorly), but still triannulate ; so, 

 too, are the segments which immediately follow, though much 

 narrower. After the clitellum the segments continue to be 

 triannulate. 



" The clitellum extends from segments xiii.-xix. ; it is at 

 first complete, extending right round the body ; but on 

 segments xvi.-xix. there is a ventral median area without any 

 glandular modification. 



"The atrial pores are upon very conspicuous papillae; the 

 two of each side of the body are connected by a longitudinal 

 groove, which is not straight, but has a semicircular outline, 

 the convexity being dorsal. The oviducal pores are just in 

 front of the ventralmost seta. The setas are rather distant 

 from each other ; a somewhat greater distance separates the 

 two lateral setse. 



" I have not seen any dorsal pores. 



" The pharynx occupies the first four segments of the 

 body; the gizzard is very elongated, with parallel margins ; it 

 measures 65mm. in length ; the gizzard occupies tNvo com- 

 plete segments, the fifth and the sixth. The oesophagus bears 

 in segment xvii. the single pair of calciferous glands, which 

 present the appearance of an oval swelling of the oesophagus 

 itself. The intestine commences in the nineteenth seg- 

 ment. 



" The septa of some of the anterior segments are, as is so 

 constantly the case with earthworms, strengthened and bound 

 together with thin muscular strips, which occasionally pass 

 through one septum to reach another lying behind it. The 

 first septum, which is thin and transparent, divides seg- 

 ments iv./v. ; it is traversed by a large number of muscular 

 threads which bind the pharynx to the pariatis. The next 

 septum is also thin and delicate in texture ; it is attached at 

 the end of the first third of the gizzard ; a good number of the 

 threads which bind the pharynx to the pariatis pass through 

 it. The following seven septa are thickened ; the last of 

 them, therefore, bounds the thirteenth segment anteriorly. 



" The dorsal vessel is completely double ; the two tubes 

 of which it is composed retain their individuality when they 

 pass through the intersegmental septa. Tlie dorsal vessel is, 

 however, at first a single tube; it is not until the seventh 

 segment that it becomes double. In this segment commences 

 the supra-intestinal vessel, which is large and very conspicu- 

 ous. In segments x., xi., xii., xiii. are the four pairs of 

 dilated hearts ; in a few segments, anterior to the tenth, are 

 more delicate peri-oesophageal vessels. 



" There are, as in OctocJuetus multiporiis, a pair of large 

 nephridia lying close against (in front of) the first septum ; 

 from each of these a slender duct was traced forwards which 



