148 NERILLA ANTENNATA. 



1854. Nerilla antennata, Leuckart. Archiv Naturges., 1854, p. 327. 

 1863. „ „ Claparede. Beobacht., p. 48, Taf. xii, f. 16—20. 



1865. Dujardinia „ De Quatrefages. Annel., II, p. 69. 



1877. Nerilla „ Barrois. Compt. Bend. Ac. So., t. lxxxv, p. 288. 



1883. „ „ Levinsen. Vidensk. Meddel. Foren. Kjobenh, p. 250. 



1884. „ „ Webster and Benedict. Bep.U. S. Comm. Fish for 1881, p. 711, pi. ii and 



iii, f. 17—23. 

 1893. ,; „ Flor. Buchanan. Kep. Brit. Assoc, 1892, p. 358. 



Habitat. — Plymouth (Miss F. Buchanan). 



Faroe Islands (0. Schmidt). St. Vaast-la-Hougue, and other shores of France 

 (Claparede and Barrois). Amongst corallines at Chausey (De Quatrefages). 



Head (fig. 51) rounded, bearing three rather long, articulated tentacles, a median 

 and two lateral. The palpi (?) are small, clavate, and lateral in position. Byes four, 

 brown, the anterior pair wider apart than the posterior ; all are provided with lenses. 



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Fia. 51.— Head of Nerilla antennata. Enlarged. After Claparede. 



Body (fig. 50) about 1 mm. long, and of nine segments, the first bearing a pair of 

 articulated cirri shorter than the tentacles. The mouth is large and somewhat triangular, 

 and it is followed by a muscular pharynx and a stomach. No constrictions appear on 



._ _.;o 



Fia. 52. — Foot of Nerilla antennata. Enlarged. After Claparede. 



the intestine, which in the middle region is glandular. Numerous tufts of vibratile cilia 

 occur on the body, and one on each side behind the foot. Segmental organs are present. 

 The body terminates in two cirri posteriorly. 



Foot (fig. 52) with only a lateral cirrus and simple capillary bristles. A glandular 

 organ occurs in most of the segments of the body after the first, with a ciliated opening 

 between the feet. The gland has refracting corpuscles (Claparede). 



Reproduction. — Ova large, developed in the lateral region so as to affect the outline 

 of the body. In the males the sperms float freely in the body-cavity. 



Claparede thought that this form lay between the errant and the sedentary annelids. 

 The free condition of the alimentary canal in the body-cavity, and the absence of 

 dissepiments and compound bristles are interesting. Barrois (1877) found both males 

 and females and observed the development. 



Levinsen (1883) makes a new family for this genus, viz. Nerillidse. Until further 

 investigation is made, however, it is, perhaps, well to leave the genus as an appendix to 

 the Syllidas. 



