SCOLECOLEPIS VULGARIS. 159 



segment anteriorly shows two rings. Behind the middle, however, the donble ring is 

 indicated only in the median band. The general colour is yellowish-brown, the ventral 

 surface inclining to fawn. Dorsally the rich red of the transversely arranged branchise 

 give it a general ruddy hue, whilst ventrally the median blood-vessel causes a dull or 

 slightly reddish longitudinal band ; segments one hundred and twenty to three hundred 

 (De St. Joseph). The buccal segment shows two small pads or papillaB ventrally — one at 

 each side of the mouth, and dorsally it forms a process at each side of the snout behind 

 the short anterior tentacles. 



The fecal masses consist of fragments of algse, ova of other forms, fragments of 

 sessile-eyed crustaceans, and a little muddy debris. 



The first foot (Plate XCVII, fig. 3) differs from that in Nerine, since it carries a 

 distinct though small branchia, the vascular loop of which does not go quite to the tip. 

 A somewhat hatchet-shaped lamella with its dorsal edge produced into a lanceolate, free 

 tip follows, and represents the rest of the upper division, whilst the inferior has an almost 

 semicircular flap. The hypodermic tissue in these flaps is somewhat regularly arranged 

 in a radiate manner. The bristles of the upper division form a fan, and are in two 

 sections, the dorsal much longer, more slender, and more finely tapered, and an inferior 

 group of shorter bristles also with finely tapered tips. Both sets are directed obliquely 

 upward and inward. The bristles of the ventral division form a fan-like row similar in 

 structure to the shorter series above them. All these bristles lie in front of the lamellae. 



The form of the foot gradually changes, so that at the tenth (Plate XCVII, fig. 8 a) 

 the superior lamella has been elongated vertically, its upper edge embracing the branchia, 

 whilst its inferior forms a rounded lobe ventrally. The upper group of golden bristles 

 still points dorsally, but they are now shorter, whilst the lower group in this division 

 forms a long row in front of the lamella. All are curved backward and finely tapered, 

 have no trace of wings, and have longitudinally striated shafts (Plate CV, figs. 2 and 2 a). 

 The lamella of the inferior division is short and somewhat hatchet-shaped, and has in 

 front of it the row of rather short, strong, and finely tapered bristles. Just as those in 

 the upper division are visible in the notch beneath it, so those of the inferior division are 

 seen in the notch above the lamella. Beneath the foregoing is a small lamella probably 

 homologous with the papilla present in Nerine. The branchia on this foot has consider- 

 able dimensions. 



No noteworthy change occurs in the twenty-fifth foot, except the increase of the 

 ventral lamella, and the same may be said as far as the fiftieth. About the fiftieth, 

 however (Plate XCVII, fig. 3 b), the elongation of the ventral lamella is conspicuous, and 

 a series of long, winged hooks occur in this division. These have stout, curved shafts, a 

 strong and sharp main fang, and two well-marked spikes on the crown (Plate CV, fig. 2 b). 

 The lower hooks project beyond the margin of the lamella, the upper, which reach about 

 one quarter from the top, being within the margin. Short bristles accompany the hooks, 

 and about three are prominent ventrally. The notch between the divisions of the foot is 

 larger, but less deep than in front. De St. Joseph found that the hooks made their 

 appearance between the thirty-ninth and fifty-second, whilst Mesnil found that they 

 appeared between the thirty-fifth and thirty-seventh. A typical foot in life is shown in 

 Plate XC, fig. 5. 



