POLYCHAT LARV#. 589 
cerned, the worm becomes a small but perfectly normal 
Polynoid before abandoning the pelagic habit. The cilia 
on the parapodia are often found in the very latest pelagic 
stages. 
Hacker described the development of a species of 
Polynoé in 1894, and published a more complete and fully 
illustrated paper on the same subject in the following year 
(1895). THe described the internal anatomy as well as the 
external characters of these larvae, and in general his 
account applies to the Port Erin species also. In his 
larvae, however, there were only seven primary segments, 
and no segment developed between the first appearance of 
these and the end of the nectochaeta stage. The same 
author described and figured the same (?) species of 
Polynoé larva from Naples (1897: pp. 77-8, Pl. III., 
fies. 1-2), and a species with nine primary segments from 
the Atlantic coast collections of the German Plankton 
Hxpedition (1898S: pp. 8-9, Pl. I., fig. 1). 
De Saint-Joseph (1895: pp. 196-198; Pl. XI., figs. 
15-17; Pl. XII, figs. 25-26) also describes the metatrocho- 
phore and nectochaeta stages of a Polynoé with seven 
primary segments. The larvae of Leprdonotus squamatus 
described by Fewkes (1885: pp. 185-186; Pl. IIL., figs. 
1-4; Pl. IV., figs. 14-17) have only four primary seg- 
ments. The development of Lepidonotus squamatus—a 
species recorded from the L.M.B.C. area—has been 
described by Leschke (1903: pp. 129-130; Pl. VI., fig. 
14; Pl. VII., figs. 1-2). The Trochophore is stated to 
have a violet pigment in the stomach walls, and a single 
pair of eyes of crescentic shape, two other pairs appearing 
later just asin the commonest Port Hrin larva. Further 
development, however, shows the appearance of only seven 
primary segments; and in the specimen shown in fig. | 
of his Pl. VII. one of the three pairs of eyespots is situated 
