640 OLIGOCHAETA 



XIX bundles of four copulatory setae, long and ornamented, like the other cUtellar 

 setae. Six pairs of oalciferous glands. Three pairs of spermatheaae in VII, VIII, IX. 

 Hah. — Surinam. 

 The distinguishing character of this species is the bundles of copulatory setae, 



which, as has ahready been suggested, represent the copulatory organs of Microchaeta. 



Possibly when more fully mature specimens are accessible these bundles of setae will 



be found to possess glands, as in Microchaeta. 



(3) Rhinodrilus gulielmi (Beddaed). 



Thamnodrilus Gulielmi, Beddaed, P. Z. S., 1887, p. 154. 



E. (Thamnodrilus) Gulielmi, Beddaed, P. R. Phys. Soc, 1891, p. 269. 



Definition. Length, 150 mm. CUtellar setae longer and with more marked ornamentation 

 than hody setae. Clitellum, XV-XXV. Six pairs of calciferom glands in IX— XIV. 

 One pair of spermatheaae in VII. Hob. — British Guiana. 



This species was first referred by me to a distinct genus — Thamnodrilus; it is, 

 however, quite a typical Rhinodrilus, though easily separable from the other 

 species of the genus. The colour of the preserved worms is purplish on the dorsal 

 and reddish yellow on the ventral surface. The species is a stout one (see woodcut 

 figure on p. 637 above). The segmentation is a little difficult to understand. In 

 my paper upon this worm I placed the first pairs of setae as well as the first 

 nephridiopores upon the second segment of the body; the (supposed) buccal 

 segment lying in front of this is, however, divided into two by a transverse 

 furrow. The fact that these two rings were both marked by a longitudinal 

 groove led me to infer that they were both parts of but one segment. If, however, 

 we allow that the supposed buccal segment is in reality the equivalent of two 

 segments both of which, as in R. ecuadoriensis, are devoid of setae, the position 

 of the organs wiU be more in accord with that of other species. For example 

 Benham (11) places the first pair of nephridiopores upon segment iv, the first pair 

 opening into the buccal cavity. In the species here described the first pair do 

 not open into the buccal cavity but on to the exterior ; and the segment upon 

 which they open will be in this case the third. This will bring the second 

 pair to the fourth segment — exactly what we find in R. ecuadoriensis. The last 

 segment of the clitellum will be, if this enumeration is correct, the twenty-sixth 

 instead of the twenty-fifth ; and Hoest names this as the last clitellar segment of 

 R. tenkatei. On the other hand, I am not able to be quite certain about the correctness 



