512 SCOLOPLOS ARMIGER. 



The peristomial segment follows as a larger truncated cone. According to the degree of 

 extrusion of the proboscis a rounded or a somewhat cylindrical process projects from the 

 mouth, or a foliate rosette of six or seven lobes, like those of Anthostoma, lie over (i.e. 

 beneath) the mouth. 



Body 3 to 6 or more inches in length, flattened and widened in the anterior region 

 before tapering to the pointed snout. Behind this anterior region the body is rounded 

 ventrally and flattened dorsally, and it continues so to the tail. The segments are distinctly 

 marked. Colour of a deep but not a bright red, inclining to orange posteriorly. Others 

 are of a general orange colour. The dorsum has a bluish-green iridescence anteriorly. In 

 ripe males the posterior region is cream-coloured. The body diminishes considerably 

 posteriorly and terminates at the vent, the rim of which apparently is divided into four 

 papilla3, whilst on each side is a long slender cirrus. In an example from Symbister 

 Harbour, Whalsey, Shetland, the tail (Plate LXV, fig. 4 a) has in addition to the papillae 

 (four) two other processes besides the cirrus, but as this tail had been reproduced the 

 exact nature of these additional processes is uncertain, and they may have been abnormal. 

 In another example from the same site the tail corresponded with the type, viz., had four 

 small lobes or papillae and two long cirri. These cirri show peculiar hypoderm, the 

 granules and cells towards the tip often being isolated. In all the slender posterior region 

 has proportionally much longer branchiae and foot-processes, so that it is hispid or fringed 

 in a characteristic manner. 



The muscularity of the body- wall anteriorly is great, the vertical and transverse 

 muscles being apparently strong. As soon as the nerve-cords reach the ventral surface 

 they lie under a broad band of muscle continuous in the middle line and apparently 

 homologous with the oblique muscles. When the body-wall is completely formed the dis- 

 proportion between the dorsal and ventral longitudinal muscles is great. The dorsal are 

 comparatively thin and narrow, whereas the ventral form nearly half the area of the 

 body in section. Each is a massive muscle stretching almost to the dorsal edge of the 

 body, and increasing in diameter to the mid- ventral line, where it is deepest. The nerve- 

 cords are carried inward, and are connected with the hypoderm only by a very narrow 

 pedicle. The area is ovoid, with a large neural canal superiorly. The inner border of 

 each muscle often separates along with the nerve-area in section, a condition which, 

 perhaps, occurs more easily from the fan-like series of fasciculi, which traverse the muscle 

 from the great vertical band on each side of the gut. The oblique muscles, which are 

 fairly developed, are fixed to the outer edge of the upper arch of the area. 



Very fine examples from Lochmaddy, North Uist, have the median ridges of segments 

 running from the feet ventrally well developed, especially posteriorly. In a specimen 

 from Balta (four to five fathoms) the lateral fillets below the ventral division of the foot 

 are tinted brownish in the spirit-preparation, as if from pigmentary deposit, from the 

 twenty-first foot to the fifty-first, the end of the fragment. 



The anterior region consists of about eighteen segments, having shorter, stouter, 

 serrated bristles. The feet are little developed, though from the first segment backward 

 two bristle-bundles, which soon assume distinct characters, are present. Thus at the 

 fifteenth foot the dorsal division has a conical dorsal cirrus of considerable size, whilst in 

 front of it, and arising from a rounded elevation, is a tuft of rather long bristles, the shafts 



