NEREIS PELAGICA. 273 



VIII) trends to the ventral surface. Area V seems to be represented by an acutely 

 triangular space between and behind VI. Ventrally (Plate LX, fig. 6 a) a belt of prickles 

 (IV), broader at the outer or ventral edge, occurs below the jaw r s in a corresponding 

 position to the dorsal crescents, though with a different arrangement of the constituent 

 prickles. In the median line on an eminence is a central group of small prickles (III), 

 about eight in number, and on each side a short lateral crescent of three prickles. 

 The band of points (VII and VIII) from the dorsal elevation with the four horny teeth 

 extends across the ventral surface, the arrangement of the prickles being somewhat 

 modified by the mapping out of the area by the depressed lines. The general effect, 

 however, is to produce a belt, with the larger prickles, in some cases, forming an anterior 

 row, and a belt of more numerous small prickles behind, the smallest points being 

 posterior. In some of the areas marked off by the depressed lines two or three of the 

 large points occur in front and a group of the smaller behind, and an indication of 

 symmetry is seen especially in the lateral areas. Little variation is found in the 

 arrangement and proportional size of the paragnathi. 



The food consists of delicately branched Algae, coarse fragments of Fuci and other 

 sea- weeds, sandy mud, sponge-spicules, small ova, bristles of other polychaetes — probably 

 swallowed with portions of the bodies. The faecal masses are enveloped in a coating of 

 mucus. 



The first foot (Plate LXXI, fig. 7) has dorsally a prominent edge ending in the 

 cirrus, then a large lobe smoothly rounded distally. Beneath is a somewhat pointed 

 conical setigerous process bearing two tufts of bristles and a spine, the upper tuft having 

 the terminal pieces long and serrated, with the exception of one with a short serrated 

 terminal process. The lower group consists of bristles with short terminal pieces. 

 Inferiorly is a lobe of similar shape externally to the dorsal, but as the ventral cirrus 

 springs from the base close to the body, it is more conspicuous and has a slightly sinuous 

 ventral margin. The second foot is more or less like the first, the elevation at the base 

 of the dorsal cirrus being more prominent, but the third has two lobes above the conical 

 setigerous process, viz., a smaller upper, and a lobe resembling the dorsal of the first foot. 

 Between them, however, is a tuft of bristles with long spear-tips. There are now two 

 spines. The setigerous region remains conical, and the inferior lobe has increased in 

 bulk. The dorsal cirrus is shorter. 



The tenth foot (Plate LXXI, fig. 7 a) presents in the dorsal division two nearly 

 equal lobes with the bristles between, the dorsal bearing the cirrus, whilst the ventral 

 division consists of the conical setigerous and a rounded ventral lobe with a cirrus at its 

 base. All the bristles in the upper division have long slender tips. Those of the ventral 

 division form two groups. In the upper group most have long tips, but three or four 

 have short tips. In the lower group a few of the upper have long terminal pieces, the 

 rest short tips (Plate LXXX, fig. 25). 



The thirty-seventh foot (Plate LXXI, fig. 7 b) has the two lobes of the upper division 

 considerably more pointed, so that they form elongated cones. The shafts of the bristles 

 have greatly increased in strength, and one or two with short tips and strong shafts are 

 present. In the inferior division the two groups are equally differentiated, those with 

 slender shafts having long slender tips (Plate LXXX, fig. 25 a), whilst those with stout 



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