of tlw Virginian Coast. 51 
POLYDORA Bo8C. 
POLTDORA HAMATA 71. Sp. 
PL. VIII, FIGS. 111-116. PL. IX, FIGS. 117 ,118. 
Head emargiuate in front, outer angles rounded, directed 
outward and forward. 
Eyes four, black, between bases of tentacles; the anterior 
pair larger and further apart than the posterior. 
Branchiae begin on the seventh segment, 38 pairs, short, 
flattened, not tapering; bluntly rounded, almost truncate 
externally. 
There is no terminal sucker, but in its place are two 
somewhat quadrangular lobes (f. 118), each with a short 
lateral cirrus. Anal opening surrounded by a circle of 
low papillae. 
Setse. On the anterior segments are the ordinary ca- 
pillary setae, simple acuminate (f. Ill) ; after the change 
of setae, these are confined to the dorsal rami. On the fifth 
segment there are two kinds of setae ; in the upper series 
from 8 to 10 stout, flattened setae, slightly curved near the 
end, not differing much from each other but with no two 
exactly alike (f. 112) ; in the lower series from 4 to 6 short 
capillary setae, for the most part like f. Ill, but sometimes, 
as in f. 113, widened at outer third. 
From 15 to 24 of the posterior segments are furnished with 
stout hooks, one to each dorsal ramus (f. 116) ; with these, 
in addition to the ordinary capillary setae, is one much 
longer than the rest (f 117). The change of ventral setse 
takes place on the 7th segment, though a few capillary 
setae are found on that segment. The anterior ventral 
setae (f. 114) after the change, are somewhat stouter than 
the posterior (f. 115), all bidentate, covered at the end 
with a membrane, as shown in the figures. 
The anterior part of the body is rounded below and 
