488 THE ANNELIDA POLYCHAETA. 



band embracing also the first somite and adjoining the second. The papillae 

 and the outer paleae are yellowish. The second somite is deep purplish brown 

 in the dorsal furrow and a lighter, greyish brown adjoining this and down the 

 sides. The third segment is similarly colored excepting that the grey-brown is 

 confined to the anterior margin. Elsewhere these somites are yellow. The 

 remaining part of the body is yellow, excepting for a short transverse stripe of 

 dark purplish brown just above each neuropodium and extending a little past 

 the lower end of the series of uncini. These dark spots become heavier caudadly. 

 The caudal portion of the body in the type is missing. As it is, there are 

 twenty-four abdominal somites, making with the thoracic a total of twenty- 

 nine. The length is 45 mm. The maximum width across anterior end of 

 abdomen 7.5 mm. The width across opercular folds, near 10 mm. 



The mouth is a small opening bordered in the usual way by the thin palpal 

 folds. 



The opercular lobes are widely divergent. Each opercular plate viewed 

 from above is very narrow. It bears two rows of paleae, an inner one of dark, 

 smooth ones, and an outer one of larger, yellow plumose ones which are nearly 

 thirty in number and about twice as numerous as those of the inner row. At 

 the caudal end of the series of paleae on each side is inserted a single stout, black, 

 nuchal hook, the distal part of which bends in horizontally but is not recurved 

 toward base. Along the outer side of the ectal paleae is a series of eighteen 

 or twenty short, slenderly conical papillae. These do not vary much in size 

 excepting the most caudal, which overhangs the nuchal furrow and is conspicu- 

 ously stouter than the others. 



Branchial plates oblique, with the outer ends curving cephalad. Twelve 

 in number on each side. The filaments moderate in length, when extended 

 apparently not reaching across the peristomial region. The filaments are dark 

 purplish brown, while the plates are pale across their distal borders. 



Behind the mouth is a pair of broad, subconical folds meeting at the middle 

 line; these are pale along the mesal border, but elsewhere dark. From the outer 

 side of each of these arises a smaller, pale, conical cirrus and at the outer base 

 of the latter, in turn, a small setigerous papilla. 



The next, or second, setigerous somite is not separated from the first ventrally. 

 On each side it bears three cirri which are all stout, conical, and acutely pointed. 

 The most dorsal, corresponding in form and position to the branchiae of the 

 following thoracic somites, is the largest of the three, but is distinctly shorter 

 than the length of the somite. The most ventral one is next in length. Below 

 the ventral cirrus arises a fascicle of long setae. 



