580 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
larva. No cilia have been detected upon any other 
segment. 
The larva is transparent and almost colourless except 
for material in the gut, two pairs of opaque, dark brown 
or black eyespots on the dorsal surface of the pro- 
stomium, and traces of opaque pigment on _ the 
prostomium and on the posterior surface of the anal 
segment. 
Syllid A (Pl. I., figs. 1 and 2).—This, the most 
plentiful, is characterised by the setae shown in fig. 2; 
one of the simple (anterior) and four or five of the 
compound setae occur in each tuft. Anal styles are 
present in every specimen, being indicated even in the 
Metatrochophore shown in PI. L., fig. 1. 
In the oldest specimen obtained there are seven 
chaetigerous segments, the parapodia of the first of these 
still being shorter than those of the segment immediately 
behind them ; both dorsal and ventral cirri are present on 
every parapodium, the dorsal at its base, the ventral 
about half way along it; the dorsal cirrus is larger than 
the ventral. The two pairs of peristomial cirri are both 
present, the dorsal being about 100 long, and the ventral 
rather less than half that length; the dorsal pair are 
very slender, and transparent distally. There is no trace 
of cephalic tentacles or palps. In one Nectochaeta of this 
species a stout aciculum, slightly curved distally, is 
embedded in the tissues at the base of the peristomial 
c1rrl. 
Syllid B (Pl. I., fig. 3) This species is characterised 
by the presence, in each tuft of setae, of two simple 
capillary setae, one shorter and more slender than the 
other, and several compound ones, the latter each with a 
long filamentous distal segment (PI. I., fig. 3). 
The two youngest larvae seen both possess five pairs 
