9 
hesitated in referring a species A. Cobbii to it because of the 
lateral organ not being spirated as in A. elegans. I shall remark 
here that, if all the species hitherto described as Aræolami really 
belong to this genus, we shall 
have the phenomenon of a genus 
in which four — at least three 
— different types of lateral or¬ 
gans occur. Even if we do not 
count the A. Cobbii Steiner we 
shall have A. elegans with spiral¬ 
shaped lateral organ, A. bioculata 
and A. mediterranea with cir- 
cular lateral organ and A. micr- 
ophthalmus and A. spectabilis 
with loop-shaped lateral organ. 
Fig. 4. Aræolaimus spectabilis ; 
tail of female. 
Without for the present entering 
on a discussion of the relationship of these forms I shall how- 
ever only here call attention to the strange feature that an organ, 
having, as far as I am aware, hitherto generally been considered 
as of generic value among Nematodes, exhibits such an inconstancy 
in a single genus. 
In the species under consideration the shape is much like that 
of A. elegans; the body is rather siender and attains its greatest 
width in the neighbourhood of the vulva,* where it is somewhat 
expanded by the reproductive organs. In the front end it begins 
to taper at the level of the base of the æsophagus; then it tapers 
evenly to about at the level of the excretory pore where it begins 
tapering more quickly. In the region of the ventral giand and at 
the level of the ampulla for the excretory duet the body is some¬ 
what expanded (fig. 5). 
The cuticle is smooth. The irregularly scattered setæ, often 
seen in this genus are very scanty in the species from the Auckland 
Isl. and mainly restricted to the front end. On the head four setæ 
are seen, arranged in one ring. More caudad, at the level of the 
lateral organ, two longer bristles are seen and behind them two 
more, subventrally situated. The eyes are of about the same shape 
as in A. microphthalmus de Man; their place is 40 p caudad to 
the front. The lateral organ is, as above mentioned, loop-shaped 
