GUSTAV EISEN: PONTOSCOLEX 



setae with those in the anterior 20 somites, I find that the former are about three and 

 a half times larger and wider (figs. 4, 5 and 6). The small anterioi also 



much more sigmoid than the posterior on< - and much m< han the corresponding 



setae of Pontoscolex corethrurus as figured by Perrier (I. c. fig. 10. a pi. iii). Nor 

 the setae show any ornamentation. My specimens did not possess a developed cli- 

 tellum, and the setae in the clitellar somites were in no 1 different from the 



other anterior setae. 



In the middle of the body the seta' are just as described by Beddard in his 

 Pontoscolex (Urochaeta) sp. from Queensland. The setae a and e retain their position 

 in the row from head to tail, while setae b and d disperse irregularly without any 

 systematic recurrence. The most posterior setae are so arranged that eight setae form 

 a square, there being three setae in each side of the square or rhomb. In somite ii 

 the setae are not larger than in somite iii, but setae c are placed about in line with 

 d in iii, and d in ii is slightly more dorsal than setae d in iii. But setae c and d in 

 ii are in this species much less displaced than in Pontoscolex corethrurus, in which 

 species the setae in ii are larger than those in iii. 



Interior characters. The interior characters could not all be made out, 

 but I believe the testes to be in xi, the single pair of rosettes in xii. The most 

 important internal character is derived from the form and location of the sperma- 

 thecae which are smaller than in any other species. The supra-cesophageal gl and is 

 very much as in P. corethrurus. Septa. There are four thickened septa separating 

 vi vii, vii viii, viii ix and x xi. The septum which would be expected between ix x 

 is wanting, just as in P. corethrurus, but it is on the ventral side represented by 

 a row of septal muscular bands which pass from the intersegmental groove of ix x 

 backwards to septum x xi, and against the anterior face of which rest the two 

 posterior spermathecae, those between ix x. All the thickened septa are very strong 

 and composed of distinct muscular bands, which are so tough, that dissection is difficult. 



Spermathecae. These are found in three pairs in somites viii, ix, x and 

 the spermathecal pores are situated in the posterior part of the somite immediately 

 in front of the septum in line with setae a and b. The location of these pon 

 exactly the same as I have found it to be in Pontoscolex corethrurus mexicanus. The 

 exact location has not been mentioned by any previous investigator, and Beddard 

 simply refers to the spermathecae in Pontoscolex corethrurus as being situated in vi, 

 vii and viii. Other investigators again refer to the spermathecae as being in vii, viii 

 and ix, which probably only means that the body of the spermatheca i- respectively 

 in those somites, while the pores are in those situated next anterior. In Ponlost 

 Ltlljeborgi the pores and the spermathecal sacs are situated in the same somite. 



