20 Prof, M‘Intosh’s Notes from the 
encysted Distomes, which might have been introduced by 
the Rissoe. 
The second species 1s Nerinides tridentata, Southern *, from 
Blacksod Bay in Laminarian roots. The snout is pointed, 
with a median ridge which in lateral view forms two divi- 
sions—an piberior: less elevated and a posterior terminating 
in the more or less adnate tentacle. In the line between 
the two divisions are the four black eyes arranged in a trans- 
verse row. The mouth opens inferiorly, and the extruded 
proboscis is bell-shaped and smooth. The tentacles were 
absent in the example kindly sent by Mr. Southern, but he 
describes them as “short, thick, and firmly adherent, of a 
deep chocolate colour.” 
The body is nearly an inch in length (16-20 mm.) in life, 
tapered a little in front and more distinctly diminished 
posteriorly, where it terminates in two small rounded lobes, 
a slight dorsal process indicating the upper edge of the anus. 
Segments 61-70 short anteriorly, wider in the middle region. 
Dorsal surface flattened, ventral rounded. 
The first foot has a small conical papilla or cirrus, and a 
single (ventral) tuft of translucent bristles with a well- 
marked curve at the commencement of the tip. If wings 
are present they are very narrow. The second part bears 
dorsally a small branchia curved inward, the dorsal lamella 
being fused to“it and ending inferiorly in a truncate edge. 
A tuft of finely tapered translucent bristles spreads lke a 
fan upward and outward. The upper bristles of the tuft are 
longer and more delicately tapered, and the wings in these 
are less distinct than in the shorter and thicker forms at the 
lower edge. The inferior division has a bluntly rounded 
lamella and a shorter tuft of bristles with traces of wings. 
At the tenth foot the branchia is larger, forming a broad, 
flat, curved process, the soldered lamella of the superior lobe 
ending inferiorly in an edge which projects less than the 
upper margin of the ventral lamella. The dorsal tuft of 
bristles has the same structure as in the second, only they 
are in two rows, are longer and stronger, and the tips 
less elongated. The lamella of the inferior division has 
increased in depth, and the bristles are proportionally 
longer and still stouter than the dorsal. Both tufts have 
a distal curve. Southern describes a group of three slender 
striated setee on the lower margin of the ventral bundle. 
* Proc. R. Irish Acad. vol. xxxi. No, 47, p. 98, pl. x. fig. 23 a-s. 
