PHYLLOCBLETOPTERITS GRACILIS. 131 



small tentacles on each side of the median fold of the rim of the oral funnel dorsally 

 corresponds with Phyllochsehof terns. The anterior region, which, fortunately, is complete, 

 consists of ten bristled segments and only a single segment of the succeeding region remains. 



The buccal segment shows a prominent thick rim all round, the ventral part, however, 

 being not more so than the dorsal, which forms a transverse projection from which a 

 grooved ridge runs backward and ends in a point. At first sight this appears to be only 

 a fold of the buccal funnel, but closer inspection reveals that it is a specially differentiated 

 structure, the anterior ends of the ridge on each side ending in a small, rounded boss, to 

 the exterior of which, and in front of the short tentacle, is an area with a minute papilla 

 or two which may represent the site of the large tentacle (palpus), now removed. The 

 smaller tentacle on the left is somewhat subulate, but that on the right is widened a little 

 below the tip so that it is more or less clavate. They are somewhat widely separated at 

 the base in the preparation, lying just behind the little papillse indicating the palpi, but 

 considerable distortion often follows preservation. From the apex of the grooved ridge 

 at the anterior border of the dorsum a median band extends along the firm convex 

 muscular surface to the posterior border of the region, and the feet on each side are 

 boldly marked. Ventrally the preparation shows a slightly flattened surface, equally 

 firm. Anteriorly the lower lip is dark grey, a whitish band follows, and then another 

 dark grey area covering two segments. A transversely elongated whitish area succeeds, 

 occupying the site pertaining for the most part to the sixth feet. The ventral region 

 behind this patch is a shade lighter than the grey area in front. 



With the exception of the fourth the ten pairs of uniramous feet are nearly uniform 

 in appearance, the first pair, however, being directed slightly forward, as are also its 

 bristles. Each foot as a rule is directed outward and slightly upward, the row of bristles 

 running from the base ventrally along the prominent ridge, inclining backward a little at 

 the tip, and ending in the more slender series there. The bristles of the first foot had 

 been broken or abraded, only one or two of the tips — flattened, translucent, and gently 

 tapering to a flat spear — being present. 



The fourth foot is larger than the rest and the free end is truncated. It bears 

 ventrally a single, large chitinous bristle resembling a long molar tooth (Plate CVIII, 

 fig. 15), the tip being enlarged and very hard as well as brittle. Its long and strong 

 shaft is deeply inserted into the tissues and its muscles are strong. Below the bristles is 

 a papilla with dots. Above it is a short row of the bristles with thin, hastate, or almost 

 foliate tips, the direction being upward and slightly backward. 



In general the bristles of the region commence ventrally with a regular series in the 

 form of a fan, the bristles being arranged in a row close together and up to the end of the 

 shaft, only a fragment thereof, as a rule, projecting beyond the tissues (Plate Oil, 

 figs. 6 and 6 a). The flexible lanceolate tip will thus yield as the foot is applied to the 

 wall of the tube, whilst the powerful tooth-like bristle of the fourth segment will securely 

 fix it anywhere. The tips become more elongated and acute toward the extremity of 

 the foot, and, for instance, in the tenth foot the distal series in the preparation forms a 

 separate group, the shafts of which cross the great fan at an angle, and from their position 

 project much further outward and upward. The tips of these are narrow, elongated, and 

 finely tapered (Plate Oil, fig. 6 b). 



