144 
cannot be upheld in the future. In naming the former E. pigrans 
var. novæ-zealandiæ I shall indicate, on the one hånd, that I assume 
that they belong to the same species and, on the other, that suf¬ 
ficient data for a veritable and full Identification are lacking. To 
this latter cautious view Haswell’s direct statement aS to the antral 
giands has contributed more than anything else. I appreciate too 
much Haswell’s valuable researches on Turbellaria to omit full regard 
to his descriptions. Before a satisfactory explanation as to this 
difference is obtained, I am prevented from making an identification. 
The study of the specimens from New Zealand has given the 
following results. 
First of all, with regard to the exterior appearance, Haswell’s 
statement that Enterogonia pigrans has a thickish form of compar- 
ativcly firm consistency, and has an oval or elliptical outline is 
also valid for the specimens from New Zealand. On the upper 
surface there are also a large number of dark minute spots and 
their smaller size and more scattered distribution towards the margin 
is also very apparent. The difference in colour of the spots, my 
specimens being more greenish brown, while the Australian form 
is dark olive, bears perhaps no weight at all, as in both cases the 
observations have been made on preserved specimens only. The 
measurements given by Haswell are 1 cm. in length and 5 or 6 mm. 
in breadth. The same proportions are held by my specimens, which, 
however, attain a far larger size, or from 26 to 34 mm. in length. 
It is sufficient to point out here that corresponding differences 
are in many instances met with in sexually ripe individuals, un- 
doubtedly belonging to the same species. As an excellent example 
hereof I can, for instance, refer to Prosiheceraeus vittatus in Scan- 
dinavian waters. 
I quote further: »The mouth is considerably behind the middle 
of the body, and, in the fixed specimen, the reproductive apertures 
are situated very close together, and are nearer to the posterior 
edge than to the mouth. “ For comparison with Haswell’s statement 
I shall here reproduce a photograph (Plate III, Fig. 17), where the 
openings are clearly visible. The following is said in regard to the 
arrangement of the eyes: „There are numerous scattered minute 
eyes over the brain region, and between the latter and the anterior 
margin, as well as marginal eyes running all round the periphery. 
