NEREIS (ALITTA) VIUENS. 335 



presents a tentacle and a second process (palpns ?) on each side of the snout, whilst the 

 preoral ring of cilia is narrower and the body considerably more elongate. The activity 

 of the ciliated ring is noteworthy, and in addition to its locomotor functions it may aid in 

 obtaining nourishment. Four tentacular cirri of different lengths, viz., the dorsal and 

 ventral of each pair, occur behind the ciliated ring. A long proboscis now separates the 

 mouth from the granular alimentary canal which commences at the seventh bristled foot. 

 The two anal processes are larger. The dorsal lamellae of the feet are lanceolate and 

 richly ciliated on the edge which is next the body. 



Habits. — In confinement a muscular wave occurs from before backward in healthy 

 animals, and the species is fairly hardy, the elaborate coloured drawing (Plate LI II) 

 having been made from those kept for a considerable time fifty miles from the sea-coast. 

 When dying, or when placed in fresh water, they eject the proboscis with the jaws at the 

 tip, and decomposition takes place rapidly with considerable odour. Hornel states that 

 they secrete much mucus from an enormous number ol t abides in the lobes of the feet. 

 This species is often used as bait for plaice and other fishes. About the year 1890 the 

 local fishermen began to dig for them, having found for many years that those stranded 

 on the beach after storms were valuable in this respect. 



Packard (1868) considered his specimens, which were 17 ins. in length, enormous, in 

 short, "these are princes amongst worms, ranking above the smaller forms by their superior 

 size and organization and their rich imperial dress." If this able and genial naturalist 

 had seen those fully 3 ft. in length at St. Andrews his words would have been even more 

 eloquent. 



Ehlers (1868) points out that Nereis (Alitta) Brandti, the Nereis virens of Grube, 

 a closely allied species, frequents the Pacific shores of America and the sea of Ochotzk. 



A Japanese form, Nereis {Alitta) oxypoda, Marenzeller, 1 from Yokohama, shows great 

 development of the dorsum of the foot between the cirrus and the body, so that the cirrus 

 lies in a hollow between two foliaceous lobes. 



Grube's Nereis virens, 2 from the shores of Eastern Siberia, comes very near this 

 form, though Malmgren considered it a distinct species. AVhether the differences 

 indicated, such as the form of the great dorsal lamella, are due to environment and other 

 factors is still an open question. 



J. T. Cunningham (1888) 3 states that he cannot confirm the account of the nerve- 

 cords formerly given. 4 In many sections three or four neural canals are seen, which are 

 not quite symmetrical; these are sections through interganglionic transverse commissures. 

 In the cords between successive ganglia there is seen to be a single pair of canals, one of 

 which is often divided into two. The pair occupies an exactly similar position to that 

 of the neural canals in Sigalion." He adds, "Probably he" (Mel.) "examined sections 

 of the ganglia in which several canals are often seen. But these have not a constant 

 relative position, and are, I believe, due to the subdivision of the two canals which are 

 seen in the separated cords." A re-examination of the careful sections, unstained and 

 made by the hand, does not lead, however, to any change of the view stated in 1877. 



1 ' Suctjap. Annel./ p. 12, Taf. ii, fig. 3, 1879. 



3 Op. cit., p. 6, Taf. i, figs. 2, 4, 5 and 6, 1858. 



8 'Quart. Journ. Micros. Sci./ n.s., vol. 28, p. 270. 



4 ' Proc. Eoy. Soc. Edin./ 1877. 



