642. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
TABLE FOR THE IDENTIFICATION OF PELAGIC POLYCHAET 
(MrrarrocHoPpHoRE) LARVAE OCCURRING IN Port ERIN 
BAY DURING JULY.* 
1. Larva mesotrochal : Chaetopteridae. 
Larva cylindrical, with four well- 
developed ciliated bands: t ? Syllidae. 
Larva not as above: (2) 
2. Long provisional capillary setae 
present; body usually slender: (“Metachaetae,”’ 
Clap.). (6) 
Prostomium and anal segment 
bearing numerous black 
pigment-spots; each  inter- 
trochal segment with:a girdle 
of similar spots; body com- 
pact; no provisional setae:{  Pectinaria. 
Body usually compact; neither 
provisional setae nor numerous 
black pigment spots: (Nereidiformia). (3) 
3. Prototroch replaced by a broad 
band of cilia: § Eunicidae. 
True prototroch present : | (4) 
4. Body very compact; setae 
strongly toothed; rudiments 
of elytra present; (‘Trocho- 
phore monotrochal and 
characterised by overhanging 
upper lip, and presence of 
simple akrotroch, neurotroch, 
and circlet of apical cilia): Polynoidae. 
** A few species have been found which are not described above, or 
included in this table. They are all of rare occurrence, and the table will, 
I believe, be found sufficient to refer them to their systematic position 
with as much precision as is possible in the absence of a sufficient 
description. 
+ Later stages characterised chiefly, according to Hacker, by a stout 
sickle-shaped bristle borne by each parapodium. 
+ This form remains pelagic for a short time when tubicolous after 
a rapid metamorphosis. 
§ This character will not serve to distinguish Hicker’s later stage of a 
similar larva in which adult characteristics are appearing. 
