Ventral division 



290 NEREIS CULTRIFERA. 



peritoneal pigment in the middle and posterior regions, thus giving a pinkish hue to 

 the animal from its vascularity. In the female the greenish coloration exists in the first 

 twenty segments, the abdominal region being pale, variegated with black. He thinks the 

 male heteronereids are smaller. The spermatozoa are similar to those of JV. DumeriliL 

 The eggs are colourless, and 0-15 mm. in diameter. He found the metamorphosis in progress 

 in specimens about the end of March at Naples, but they were rare. The sexual elements 

 are developed in individuals of large size— apparently before metamorphosis. 



Claparede (1870) states that the following arrangement of the bristles is constant:— 

 Superior division . Homogomph with long tips. 



' Superior . • Ditto, falcate heterogomph. 



Inferior . . • Homogomph with long tips, 



falcate heterogomph. 



Bhlers again avers that there are no falcate bristles in the inferior groups of the 

 ventral division, but there seems to be a difference of opinion as to what is a falcate 

 bristle. So far as general description goes that of Claparede holds. 



Grube (1869) gave a description and figure of Nereidicola bipartia which he had 

 found parasitic on the feet of this species at St. Vaast-la-Hougue. This is probably the 

 same as Keferstein's Nereicola ovata. 



Ed. Meyer (1886 — 7) refers to a young form of this species having six bristled segments, 

 and especially to the development of the segmental organs and other structural features. 



In the collection of the British Museum this form is contained in bottles under the 

 names, e.g., Nereis ceruloea, Nereis brevimana, and Nereis pelagica. 



De St. Joseph 1 found considerable variation in the groups of paragnathi. Those least 

 variable were the two cultriform paragnathi on the dorsum of the basal segment, and the 

 double row on the ventral surface of the same region. 



Benham 2 mentions that the species is known by the name of the "Red Cat" in the south. 



Schepotieff gives in this form a careful account of the bristle- sacs, with the developing 

 bristles. 3 



Claparede 4 states that the foot-glands and the dorsal muciparous glands increase in 

 volume at the period of sexual maturity. Langerhans met with an epitokous female at 

 Madeira. 



On the shores near Cherbourg, M. Fauvel found the heteronereid in April and May. 



De St. Joseph gives a careful account of both sexes in the heteronereid condition. In 

 the female the large eyes are almost coalescent, the head and four anterior segments 

 being dull green. In the first six segments following the buccal, the cylindrical dorsal 

 cirrus is abruptly narrowed towards its extremity, and a similar condition occurs in the 

 shorter ventral cirrus. The heteronereid condition of the feet commences at the twenty- 

 second bristled segment. 



Lo Bianco 5 found JV. cultrifera mature and depositing ova at Naples from May to 

 June, the yellowish ova being enveloped in mucus on Algaa dredged at some depth. 



1 'Aim. Sc. Nat./ 7 e ser., xx, p. 215 ; 1895. 



2 f Camb. Nat. Hist./ ii, p. 316. 



3 ' Zeitschr. f. wiss. Zool./ Bd. lxxvi, p. 589, Taf. xxvi, and Taf. xxvii, figs. 1—4, 1904. 



4 ' Annel. Nap./ p. 164, 1868. 



5 ' Mitth. Zool. Stat. Neap./ xiii, p. 488, 1898. 



