304 NICOMACHE MACTTLATA. 



whitish. The nuchal grooves in N. lumbvicalis have a similar trend to those of N. 

 metadata, curving gently outward anteriorly, and separated by a flattened ridge. 



In the large Canadian Nicomache the aspect of the snout diverges still more, for 

 behind the median ridge is a deep fold of the segment, the ridge itself commencing by a 

 rather broader base, and slightly narrowing, slopes downward and forward to within a 

 short distance of the anterior edge. In lateral view a convexity exists in the middle. 

 The nuchal groove closely follows the somewhat narrow ridge and thus they converge, 

 since the ridge itself is narrower in front. The groove turns sharply outward on each 

 side, making a small augle with the main furrow, and this differs from either N. lumbricalis 

 from northern Europe or N. maculata, in both of which the curve is bold and rounded. 



Immediately behind the mouth in N. maculata is a transverse furrow indicating the 

 anterior border of a narrow segment devoid of bristles. It is marked by a distinct band 

 of pigment on the dorsum, at a distance behind that at the anterior border of the peri- 

 stomial segment. 



The next three segments are each distinguished by having dorsally a tuft of bristles 

 and ventrally a single powerful golden spine close to the ventral side. The dorsal tuft 

 consists of a few capillary bristles with tapered tips, some of the larger and more delicate 

 having opposite spikes. The ventral division has a single powerful spine or two of great 

 proportional size and of a light golden colour (Plate OIX, fig. 2 a). The general outline 

 of the spine is fusiform, the tip tapering to a strong and rather blunt point of a deep 

 yellow colour by transmitted light. The spine dilates from the tip downward to the 

 middle and again tapers to a blunt end inferiorly. The central and inferior regions are 

 closely striated, and in some marked by transverse lines, whilst the fine striaa pass upward 

 almost to the tip of the spine. Powerful muscles are attached to the spine, sloping from 

 the base of the organ obliquely outward. In the preserved examples the three sets of 

 hooks project prominently outward on a papilla, each from its segment about midway 

 between the dorsal and ventral borders. 



Dorsally the anterior end is pale with madder-brown grains, or speckled with white 

 on a brownish ground. A transverse S- shaped bar of white occurs on the snout dorsally, 

 the bars meeting in the middle line. The fourth bristled segment is often tinted crimson, 

 whilst in others the whole anterior region is so, the general hue of the body behind being 

 dull orange, marked dorsally by the median blood-vessel, and most show a tendency to a 

 whitish belt between the seventh and eighth segments. The anal funnel is dotted with 

 whitish grains internally. Those from Lochmaddy had a dark-brown snout, the browmish 

 hue in front becoming pale straw-colour posteriorly at the anal funnel. 



The anal cup (Plate XCII, fig. 5) forms a circular funnel with a series of short and 

 somewhat triangular processes or cirri, nineteen to twenty-one in number, and of a general 

 uniformity, though variations occur, one example presenting a continuous series of eight 

 or nine smaller cirri. The cup slopes evenly to the centre, in which is the anus. The 

 dorsal edge of the funnel externally is the shorter. In front of the anal funnel are one, 

 or two, narrow rings. 



The bristles form a double group, a ventral series of stronger capillary bristles with 

 wings, and a dorsal (Plate OIX, fig. 2) of more slender, finely-tapered forms, with opposite 

 spikes and a smooth shaft. The first three bristled segments have a dorsal series of the 



