LUMBRICONEREIS (ZYGOLOBUS) LAURENTIANITS. 391 



being posterior. At the anterior border of the peristomial segment are two globular 

 papillae of considerable size, one on each side of the middle line of the dorsum. Grube 

 considers them to be tentacular organs. 



The proboscis, the teeth of which were not examined by Grube, is armed with a pair 

 of much curved, dark brown maxillae, the points of which curve dorsally in a more 

 pronounced manner than usual in the group. Looked at from above there is, therefore, 

 a ventral curve of the blades and a dorsal curve of the tips. Their bases are articulated 

 posteriorly to processes which slope to a constriction, then to a fusiform and pointed 

 region behind (Plate LXII, fig. 6 a). The great dental (or maxillary) plates have a 

 small dark brown area directed vertically (dorsally) and bearing four teeth on each side. 

 In lateral view from the outside each of these brown areas is triangular, whereas internally 

 a rectangular process passes ventrally in the middle line. The anterior plates form a 

 symmetrical pair on each side, the front plate being the larger, irregularly triangular, and 

 with a single curved tooth directed dorsally. The second is also somewhat triangular, with 

 a single tooth directed dorsally. External to the anterior plate is a horny comma-shaped 

 patch, and on the right a horny bar curves backward from a line passing outward from 

 the anterior border of the great dental plate and joins the pale edge of the great maxillary 

 plate. It is incomplete on the left. The mandibles (Plate LXII, fig. 6 b) are pale, some- 

 what pointed behind, expanded and evenly rounded in front, with the exception of a small 

 external notch, as viewed from above. On this surface they have a transverse row of black 

 dots behind the anterior edge, and parallel lines running backward. On the ventral 

 surface the pale Tellina -shaped anterior area is marked by parallel lines, which follow the 

 outline of the double area from side to side. 



The first foot presents a small setigerous lobe with three black spines, and a group of 

 simple tapering winged bristles. The posterior lobe is large and ovate or broadly conical, 

 for it is difficult to say what the original condition was in a specimen so softened. 



The type of foot (Plate LXXIV, fig. 3, from the middle of the body) with the black 

 spines appears to be similar in the segments behind as far as the thirtieth or fortieth. So 

 far as the preparations go, two groups of bristles appear to be present, e.g., in the tenth 

 foot, a dorsal group of stronger, and another below the spine of bristles with shorter and 

 more slender tips and shafts. Three or four black spines occur in the tenth foot. At 

 the twentieth there are four or five spines, and the groups of bristles are similar. The 

 dorsal bristles (Plate LXXXII, fig. 8) have a bold curve at the commencement of the 

 wings, which are finely striated from the edge downward and backward. The group 

 below the spines has more slender shafts, and the curve of the tip is bow-like (Plate 

 LXXXII, fig. 8 a). One or two long winged hooks also appear in the twentieth foot 

 (Plate LXXXII, figs. 8 b and 8 c) below the spines. The tip is dilated beyond the shaft, 

 and the diameter of the terminal region is nearly uniform with rather narrow wings, the 

 striae on which, like those of the bristles, are directed from above downward and back- 

 ward. It becomes narrow at the tip to form the neck of the hook, the main fang of 

 which is of moderate size, with a crest of four or five minute spines above it. 



The type of the narrow winged hook is also seen in Lambriconerels impatiens, 

 though no nuchal papillae are present. 



The anterior end of a small example was procured in the stomach of a haddock in 



