1007.1 



NATURAL SCIENCES OF rillLADELPlIlA. 



449 



nearly equal to A the width of the prostomium, their length slightly 

 less than tiie median tentacles and nearly or quite the prostoniial 

 width. When visible from above the ends of the palpi appear immedi- 

 ately beneath these. 



Peristomium obsolete or nearly so dorsally, almost completely 

 coalesced with the prostomium below and projecting but little beyond 

 it laterally. The mouth far forward, with prominent posterior lip. 

 Tentacular cirri (figs. 1, a and h) like the tentacles, from which they 

 differ only in being supported on very short cirrophores, the dorsal as 

 long as lateral tentacles, ventral slightly shorter. 



Metastomial region very slightly depressed, the segments increasing 

 in width slightly to the middle. The first seven, as far as the caudal 

 end of the gizzard, are short and crowded; succeeding ones are longer 

 and contain the gonads. Pygidium a small ring with rounded posterior 

 outline, scarcely distinguishable from the preceding segment. It 

 bears a short unjointed median ventral style and a pair of very long, 

 slender, unjointed cirri as long as the greatest width of the body 

 (fig. 1, c). 



Parapodia (fig. 2, a) strictly uniramal on the first seven metastomial 

 segments of sexually mature worms and on all segments of immature 

 worms. They are prominent, their length nearly equaling the width of 



Fig. 2. — SijUides verrilli. a, parapodium VIII from liohind, X 250; h, tip of 

 neuropodial aciculum, X 600; c, average neiiropodial compound seta from 

 X, X 600; d, profile and rear views of end of simple nouropodial seta, X 600. 

 All drawn from No. 2402. 



the body, slender, somewhat compressed at the base, the neuropodium 

 becoming conical distally and ending in a salient dorsal angle, from 

 which the distal border slopes ventrad, and which is supported by a 

 single stout aciculum. Anterior and posterior short lips embrace the 

 yo 



