582. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
end of the proximal segment of its compound setae (PI. L., 
fig. 4, B), this being pointed in the other two species; 
by the form of the distal segment of these setae (Pl. L., 
fig. 4, B); and by the form of the simple setae (Pl. L., 
fig. 4, A), which occur one in each bunch. 
Three pairs of parapodia only are present, the first 
two segments being as yet in no way recognisable 
externally. These three pairs of parapodia (belonging to 
segments 3-5) scarcely project at all as lobes from the 
sides of the body, but each bears a tuft of well-developed 
setae. 
Malaquin (1893, pp. 389-426) has fully deseribed and 
figured the development of <Autolytus edwardst and 
Kusyllis monilicornis; and in less detail, that of Syllas 
hyalina, Grubea, Hxogone, and a few other forms. His 
larvae are all of the same general type as the three 
described above, but differ from them in important 
specific characters. He finds that those larvae in which 
the early developmental stages are most slowly passed 
through are polytrochal, the cilia appearing very early 
and, excepting those of the prototroch, being confined to 
the dorsal surface and disappearing from before back- 
wards. In those forms, however, in which the early 
stages are abbreviated the cilia do not appear until a later 
period, and then only on the head and posterior segments. 
Finally, in extreme cases, the cilia are not developed at 
all. Some larvae of this last type—Hzogone gemmefera, 
Sphaerosyllis pirifer, Syllides pulliger (?), and Grubea 
limbata (?)—are carefully described by Viguier (1884) ; 
these larvae also conform to the same general type as the 
other Syllid larvae. Of this same form also are the four 
species of atrochal larvae belonging to the tribe Exogoneae 
and the polytrochal Odontosyllis larva described and 
figured by De Saint-Joseph (1886: Pl. X., figs. 76, 78-80, 
