NEREIS CULTRIFERA. 281 



Palpi massive, the distal process encircled by a band of brown and with a pale tip, fused 

 to the anterior region of the prostominm almost to the bases of the tentacles. The dorsal 

 tentacular cirri of the second pair are nearly twice as long as those of the anterior pair. 

 Peristomial segment narrower than in Nereis pelagica. 



Body 6 — 12 ins., greenish anteriorly, pale brownish in the middle and again greenish 

 posteriorly, with the sinuous red or purplish blood-vessel branching in each segment, and 

 an orange or golden iridescent hue exists on each side of the vessel, whilst the feet are 

 greenish. Posterior part of each segment with a greenish-black bar, and another exists 

 anteriorly. Whitish grains on every segment after the anterior fourth, and a distinct 

 white patch at the base of the caudal cirri. Ventral surface pale and iridescent. 



The proboscis in extrusion has dark brown horny jaws with about five teeth. 

 Dorsally behind these are a single median tooth (I) and two lateral crescents (II) of 

 paragnathi, which are less developed than in Nereis pelagica . Veritrally this maxillary 

 region has two lappet-shaped patches or crescents of similar small teeth (IV), the 

 convexity being inward. In the middle line between the foregoing is a group (III) of 

 about six small teeth. In the basal division of the organ ventrally is a belt formed of a 

 conspicuous double row of isolated paragnathi (VII and VIII), the size in each row being 

 nearly equal, though, if irregularity occurs, the smaller are in the posterior row. Dorsally 

 the basal region has a transversely elongated tooth of a bluntly conical shape on an 

 elevation on each side (VI), whilst between and rather behind them are a median and 

 tw T o lateral teeth (V). 



First foot has a greater development of the dorsal and ventral lobes than in 

 N. pelagica, whilst the setigerous lobe is less. Feet generally with longer and more 

 pointed lobes than in N. pelagica, but the dorsal cirrus is rather shorter. Bristles of 

 two kinds, viz., those with long, slender, tapering tips (homogomph), and secondly 

 those with short tips (heterogomph), which have a more decided curve at the base, 

 and the spinous region is shorter. The strias are less regular than in N pelagica. 

 Toward the tip of the tail the dorsal region of the foot becomes much enlarged. 

 Claparecle 1 observes that this and the second foot have no spines, a feature formerly 

 mentioned by Rathke 2 in connection with Nereis piilsatoria. Whilst no spine occurs 

 in the first foot of the British examples examined, a spine is present in the second 

 foot. 



Epitohous Form. — Eyes large and convex, almost confluent on each side, and with 

 lenses. Anterior (nereid) region has nineteen feet ; the succeeding region has about 

 seventy-two feet furnished with swimming bristles and lamellae. Dorsal and ventral 

 cirri of the first seven feet as in N. pelagica, only the enlargement is slight in the ventral, 

 and it ceases sooner. In the fully developed pelagic foot the dorsal cirrus in the male 

 has seven or eight papillae on its lower border. An accessory fan-shaped lamella at the 

 base of the lobe beneath the superior setigerous process. Ventral lobe with a spur at its 

 base. An accessory small lamella in addition to the two at the ventral cirrus. 



1 ' Annel. Nap./ p. 163. 



2 ' De Bopyro et Nereide/ 



93 



