198 PROCEEDINGS OF THE ACADEMY OF [May, 



depressed, the remainder terete or subterete, strongly convex below, 

 more or less flattened above ; the first 4 very short, about five times as 

 wide as long, nearly straight laterally; the next (VI) enlarged, nearly 

 twice as long as the preceding, strongly convex laterally, and widest 

 in front. The others gradually increase in length until the middle ones 

 are ^ to f as long as wide. Posteriorly they again become very short 

 and close to the pygidium minute. Pygidium (figs. 10 and 11) bearing 

 a small, scarcely expanded, somewhat funnelform caudal disk as wide 

 as the small posterior segments and less than one-half the greatest 

 width of the body, the margin even, with only a very faint ventral 

 emargination and a deep dorsal cleft which passes into the slight fecal 

 groove. Anus dorsal of the center, on a small papilla. 



Parapodia of II with rami widely separated, the notopodium (fig. 7) 

 immediately behind the base of the tentacular cirrus, and consisting 

 of a minute setigerous tubercle and a short papilliform cirrus or post- 

 setal lobe ; the neuropodium at the level of the notopodia of succeeding 

 somites, but otherwise of normal form. Succeeding parapodia are 

 strictly lateral, with w^ell separated rami; the notopodia at first with 

 rather large foliaceous, postsetal lamellae projecting dorsal, and after 

 the gills appear gradually diminishing (fig. 12) ; neuropodia with longer 

 lower postsetal lamellse which practically disappear after somite ^'II. 

 Branchise (fig. 12) appear on X on all specimens studied, the fii'st very 

 small, and continue to LIII at least. When best developed they are 

 short, thick, digitiform and extend over the dorsum, meeting or nearly 

 meeting in the middle line. They have the usual structure. 



Somites II-V and VII bear capillary setee only. Notopodials of II 

 5 or 6, very slender, delicate, and wingless ; the others bear 4-6 longer, 

 slender, slightly curved, and narrowly bilimbate dorsal setae, and 

 about as many shorter, coarser, often twice-bent, bilimbate ventral 

 setse. Neuropodia bear 12 or 14 setse in 2 rows; they are similar to the 

 notopodials, but, except on II, distinctly shorter and more strongly 

 curved. Behind VII the notopodal setse (figs. 13) are at first similar, but 

 after the gills appear their number is reduced and they gradually 

 become longer, more slender and straighter, those of posterior segments 

 exceeding the diameter of the body. No notopodial crochets. Crochets 

 appears in the neuropodia at VIII, which, like the next 3 or 4 segments, 

 contains 2 or 3 accompanied by 1, or rarely 2, very delicate setae at 

 the ventral end of the series; for the remainder of the length there are 

 3 or 4 crochets and no setse. Crochets (fig. 17) are delicate, colorless, 

 strongly bent near the end and provided with a stout tooth arising at a 

 wide angle (about 110 degrees), and above it an accessory tooth; both 



