NEREIS (NEREILEPAS) FUCATA. 



339 



distal process being pale or slightly translucent. The tentacles and cirri are pale. In 

 some the yellowish buff is best marked over the bases of the feet anteriorly, leaving a pale 

 belt on each side of the central white line. The ventral surface is pinkish buff. 



The proboscis (Plate LXI, fig. 6) has dorsally in front of each palpus a group (VI) 

 of five or six small paragnathi. Upon the maxillary segment near the base of the jaws 

 is on each side a group (II) of larger, pointed paragnathi, the groups separated by a wide 

 interval, in which (I) a single tooth sometimes occurs. Ventrally (Plate LXI, fig. 6 a) the 

 basal segment has a row of larger paragnathi (VII and VIII) in front in groups of two 

 to four, and a series of minute ones behind, a long interval occurring between the dorsal 

 groups of this division of the organ. Distally are two lateral groups (IV) of distinct 

 paragnathi, the long axis being oblique, whereas the long axis of the corresponding dorsal 

 series (II) is more nearly transverse. Between them in the middle line posteriorly are a 

 few paragnathi (III) arranged transversely. The maxillae, which are strongly curved at 

 the tip, have from thirteen to sixteen teeth. 1 Paragnathi II and IV are often the most 

 conspicuous in size. 



Fig. 75. — Transverse section of the body-wall of Nereilepas fucata. Letters as before. 



In connection with the food of this species, De Haan 2 records that Lycoris fucata 

 devoured Teredo. 



In transverse section the arrangement of the ventral longitudinal muscles and their 

 reflection is similar to that of Nereis pelagica. The nerve-cords show a median neural 

 canal, and two lateral canals which are situated near the external border of each nerve in 

 the interganglionic areas (Fig. 75). 



The segmental organs 3 agree generally with the type which has already been alluded 

 to on p. 250. 



The first foot (Plate LXXIII, fig. 3) is chiefly remarkable for the large size of the 

 dorsal cirrus. The dorsal lobe is bluntly rounded, the setigerous lobe pointed, and the 

 ventral lobe is bevelled to a blunt tip. The ventral cirrus extends considerably beyond it. 

 There are two black spines passing to the apex of the setigerous region. The superior 

 group of bristles consists chiefly of those with long tapering tips and spinous edges 

 (Plate LXXXI, fig. 8), but there is at least one with a short terminal piece slightly 

 1 Levinsen gives a resume of teeth according to series I, II, etc., ' Viclensk. Meddel./ 1883, and 

 Tauber (op. cit.) notices the variability of the paragnathi. 

 3 'Zool. Record/ 1866, p. 586. 

 3 Vide Goodrich, ' Quart. Journ. Micros. Sci./ vol. xxxiv. 



