NEMERTINES OF PLYMOUTH SOUND. Dy. 
yellow than the last, the colour being intensified by the presence of 
scattered granules of orange pigment; the head was somewhat 
narrow and elongated, the eyes very distinct, the posterior being 
very slightly smaller than the anterior, and the four forming a 
rectangle. The cephalic grooves were very distinct; the anterior 
and posterior eyes on each side were united by a band of dark brown 
pigment ; there was a median dorsal white line on the head passing 
from the snout to a point just behind the posterior grooves; the 
proboscis stylet resembled that of T. vermiculatum. 
According to McIntosh this species breeds in April and May as 
wellas in the autumn. I have only found ripe specimens in autumn. 
16. T. vermicuLtatum, De Quatr., McIntosh. 
This is a fairly common species, living in weeds between tide- 
marks, and also in water of 5 to 20 fathoms, being frequently dredged 
with stones at the Duke Rock and Millbay Channel. Joubin finds 
that the young forms are without the pigment uniting the anterior 
and posterior eyes, and observes that the dorsal white line is a pre- 
ferable character in distinguishing this species. On this point I 
cannot agree with him, as, on the one hand, I have obtained many 
specimens which are without the median dorsal white line; and on 
the other, such a line, as I have already said, appears in an erratic 
manner on individuals of all these species, sometimes extending from 
snout to tail, sometimes limited to the head, and sometimes being a 
mere row of white dots. With his other remark, that the oval head 
“ est assez caractéristique,’ I quite agree. As in the case of the 
other members of this genus, the breeding period is late autumn and 
early winter, but, as in the last species, McIntosh found ripe specimens 
in spring and early summer. 
17. T. MELANOCEPHALUM, Johnst. 
T., MELANOCEPHALUM, Hubrecht. 
T. cononatuM, Hubrecht. 
I agree with Joubin in regarding Hubrecht’s two species, 7. 
melanocephalum and T. coronatwm, as really forming one, and I shall 
be surprised if his 7’. diadema does not turn out to be a variety of 
this species also. Ihave not found any specimens that perfectly agree 
with Hubrecht’s description of the last-mentioned species, but the 
description given by Joubin of 7. diadema is quite applicable to what 
I regard as a variety of T. melanocephalum. That the specimens to 
which I refer really belong to this species there can be little doubt, 
the variations by which they are connected to the type form being so 
numerous. 
NEW SERIES.—VOL. III, NO. I. 2 
