158 Dr. F. E. Beddard on a 
which is to be found in the posterior series. But the exact 
segment in which the change takes place I am not able to fix. 
The genitalia show no characters of unusual interest. The 
sperm-reservoirs are “ peri-cesophageal,” as in certain species 
of the genus, and there are two tongue-shaped pairs of sperm- 
sacs. I did not find the spermathece or their external 
pores. But as the only specimen with fully developed 
clitellum lacked this region of the body, and the specimen 
with fully developed genital papillae &c. had no clitellum, I 
did not like to cut the body-wall to ascertain whether the sacs 
were present. 
Remarks.—The tables of specific characters given by 
Michaelsen * appear to include all of the species of this genus 
which have been described, and they greatly facilitate the 
task of identification. J abstract from the foregoing account 
of my species the following four characters, which only occur, 
all of them together, in four of the species enumerated by 
Michaelsen, in which species alone there is a—so far—close 
likeness with the worm described in the present paper, viz. : 
(1) Setee strictly paired up to end of body. (2) Tubercula 
pubertatis forming a ridge on segments 20-25 inclusive (or 
about). (3) Septa dividing segments 6/10 thickened and 
enclosed cupwise within each other, followed by delicate 
septa. (4) The testicular sacs extend dorsaily so as to cover 
or nearly cover the esophagus of the segments in which they 
occur. The species in question are Zh. columbiunus, Mich.f, 
Th. darienanus, Cogn., Th. magnus, Cogn., Th. beddardi, 
Cogn. f. 
The last three species also certainly agree closely with my 
species, in that they possess at least slightly thickened septa 
dividing three or four segments, beginning with the thirteenth 
or fourteenth. But the details will be found to differ, from 
those set forth by myself above, in Th, magnus and Th. bed- 
dardi, while Th. darienanus seems to agree fairly closely in 
this matter with my species. Of Zh. columbianus, Michaelsen 
does not give any such peculiarities of septa in the neighbour- 
hood of segments 13 &e. 
Both Th. magnus and Th. beddardi differ by their compa- 
ratively slight cephalization, while in Zh. dartenanus the 
ventral setae commence in segment 7 and the dorsal in 
segment 27, which is the same condition as that which I met 
with in my species. But Zh. darienanus has quite different 
* Loe. cit. pp. 58-81. 
+ “Zur Kenntnis der Geoscoleciden Siidamerikas,” Zool. Anz. xxiii. 
1900, p. 53. 
¢{ Cognetti de Martiis, loc. cit. pp. 213, 222, 224. 
