298 W. BLAXLAND BENHAM. 
In Specimen B. 
No. of Somite. Right. Left. 
III, 1V, & V. Nephridiopore in line with 10th spot . . 10th spot. 
Wile : 45 Sth.;, .. - - eh 
ig Li " - Oth 5° itae) A OES 
VII. 2 . 4th: ey ates PES 
IX. 3 ; OER son Si sae cates 
X. 4 a ath 4. + 3s 4. Aihooes 
XI. +: » EOth 3 . sac) eeu 
XII. 
XIV, & - - LOth: (55% 44) na OL 
XIII. + + orn 
AV. 
XVII, &. } , a rae 
In this specimen the variations from the normal position are 
fewer in the posterior region of the body than in specimen A. 
The distances between the pores when normally situated are 
equal; that is to say, the space between right dorsal and left 
dorsal pores = space between dorsal and ventral pores = space 
between right ventral and left ventral pores. See fig. 17, 
where the position of the couples of chet are indicated by 
numerals. 
It is so very generally taken for granted that the nephridio- 
pores in any genus or species have a fixed relation to one of the 
couple of chetz, that it is worth while to carefully note such 
deviations from the rule, as exhibited in this table, and in that 
for Neodrilus, and to bear in mind that even in Lum- 
bricus and Allolotophora this pore is not invariably 
situated anteriorly to the ventral couple of chete. Claparéde 
and Hering pointed this out some years back, and Borelli, in 
1887, recurred to the matter,! and examined some half dozen 
of the common species of the family Lumbricide (s. s.) 
from this point of view. His results, which are not very 
detailed, show, however, that in some species, L. herculeus, 
for instance, nearly as many nephridiopores have not the 
“normal” position ashave. In L. rubellus there are more 
1 * Boll. d. Mus. Zool. ed Anat. Comp. Torino.,’ vol. ii, No. 27. 
