NEREIS (PERINEREIS) MARIONJL 301 



long lamellae anteriorly as well as posteriorly, for he was by no means scientifically 

 accurate. 



Frey and Leuckart (1847) describe and give figures of a new species, Nereis 

 suednea, from Heligoland, which appears to correspond most closely with the present 

 form. 



Grrube's Nereis vexillosa 1 from the shores of Eastern Siberia (near the Amoor) is an 

 allied form, and his Nereis arctica may be its epitokous stage. 



The characteristic condition of the dorsal lamellae of the feet posteriorly induced 

 Malmgren (1867) to institute the genus Stratoniee for this species. 



Ehlers (1S68) apparently refers to this form under two titles, viz., Nereis lamellosa 

 from the Adriatic, and Nereis suednea of Leuckart from Cuxhaven and Norderney. The 

 differences in the paragnathi are due to mere variation, as formerly explained. Both 

 have short tentacles and tentacular cirri, and the form of the foot is characteristic. 



Claparede (1870), in his account of this form, his Nereis macropus, omits reference 

 t'o Nereis Marionii (And. & Edw.), the resemblance having apparently escaped him for the 

 moment. The shortness of the tentacles and the general aspect of the head, the armature 

 of the proboscis, the nature of the feet, bristles, and other parts are more or less identical 

 with A. Marionii. He truly considered the greatly elongated dorsal lamella as an aid to 

 respiration, his figures bearing out his interpretation, and he alludes to other forms in 

 which the superior lamella is largely developed, e.g., Mastigonereis, Schmarda, P sen doner eis, 

 Paranereis, Perinereis, and Mastigonereis, Kinberg, though he does not approve of the 

 latter author's classification. 



It is remarkable how closely Nereis melarwcephala of the ' Challenger ' approaches 

 the British species, which probably has a much wider distribution than is at present 

 supposed. Slight variation may explain the differences in paragnathi and other respects 

 which are held to be of specific importance. 



Gravier's 2 (1901) Pseudonereis anomala, from the Red Sea, is another form which 

 closely approaches this species. 



An interesting criticism, with four good figures, on this species, as the Nereis 

 (Neanthes) suednea of Leuckart, and the N. Perrieri of De St. Joseph, has recently been 

 made by R. Horst, 3 who had the advantage of examining the original specimen of 

 Leuckart, as well as those of Metzger and others, in the collection of Ehlers. He comes 

 to the conclusion that these are one and the same species, and that the limited geographical 

 distribution no longer holds. If, however, he had included other synonyms in his review, 

 this distribution would have been still further extended. 



The form termed Nereis glandulosa by Ehlers 4 approaches this form in the structure 

 of the feet and other features, but it does not appear to be identical, though too much 

 reliance should not be placed on the paragnathi. 



1 ' Mem. des Sav. etrang./ St. Petersb., viii ; p. 4, pi. ii, figs. 1, 5, and 6. 



2 <Nouv. Arch. Mus./ 4 e ser., t. iii, p. 191, t. ii, pi. xii, figs. 50—52. 



3 ' Notes from the Ley den Museum/ vol. xxx, p. 215, 1908. 



4 'Deutsch. Tiefsee Exped./ p. 74, Taf. viii, figs. 1—6, 1908. 



