LINEUS GESSERENSIS. 185 



developed in May and September. Sir J. Dalyell had a specimen which discharged innumerable 

 white ova in May. 



This Nemertean was first noticed by the Rev. W. Borlase, under the name of the Sea-Long 

 Worm, but it received its scientific title from Col. Montagu. If subsequent writers on the 

 Nemerteans had had the privilege of consulting the manuscript of this author, great confusion 

 would have been avoided, and this not more conspicuously than in the present instance. He had 

 observed the variable colours — from dusky to rufous-brown, and striped more or less plainly — of 

 adults and young specimens. His description, on the whole, is excellent, though, in common with 

 many other naturalists, he omitted to notice the eyes ; and in his early account in the ' Linnean 

 Transactions' it is probable he thought the proboscis the excreta. He makes the curious 

 remark, that " It is not fragile unless contracted by spirits, for we have generally measured the 

 length by winding upon a cylinder of wood of known circumference, suffering five or six feet of 

 the animal to be pendent, in order to ascertain as nearly as possible the utmost length. In this 

 state they have been suffered to die, and rarely break by contraction. " Prof. Jameson 

 observes that it was " noticed many years ago by my friend Mr. Neill, afterwards transmitted by 

 the late Mr. Simonds to Mr. Sowerby, who has figured and described it ... in his e British 

 Miscellany/ ' He calls it the Black Worm of the Newhaven fishermen. The Rev. Hugh 

 Davies did not see the eyes, and rather vaguely conjectured that it advanced by coiling its 

 " amazing length into a compact spiral, each volution of which assisted in the act of progression," 

 a supposition only less wide of the truth than that of M. de Quatrefages, who mentions that it 

 glides through the water by means of excessively fine cilia. Sir J. Dalyell, again, considered that 

 small examples floated less by their specific levity than by the repulsion of the lubricating matter 

 investing the body, a method somewhat involved in obscurity. I am not satisfied that the 

 Opkiocephalus murenoides of Delle Chiaje is this species ; indeed, the flattened form and pointed 

 snout shown in a figure in his ' Descrizione 5 point this out rather as allied to Cerebratulus 

 angulatus, Miiller, than to the present species. The so-called specimens of Lineus murenoides, 

 also, of British naturalists, are all referable to L. marinus. I have included M. van Beneden's 

 Nemertes Quatrefagii under the same head, for it seems to be only a pale and young variety, with 

 the stripes distinctly marked. The arrangement of the eyes, as noted by this author in regard to 

 his supposed new form, is equally characteristic of L. marinus. 



2. Lineus gesseuensis, 0. F. Mutter. Plate IV, fig. 2; and Plate V, fig. 1. 



Specific character. — Eyes numerous, marginal. Snout distinctly wider than the rest of the 

 body. Greenish, olive or reddish-brown. 



Synonyms. 

 1766. Alia Lumbrici marini species, tota atra, Pallas. Miscell. Zool., p. 216, tab. 11, f. 9. 

 1771. Der Stromische Rod-Aat., O. F. Miiller. Wurm-Arten des sussen u. salzigen W., p. 118, tab. iii, 



figs. 1—3. 

 ] 774. Ascaris rubra, O. F. Miiller. Verm, terrest. et fluv. Hist., vol. i, ii, p. 36. 

 1776. „ „ Ibid. Zool. Danic. Prodr., p. 213, No. 2587. 



1780. Planaria fusca, O. Fabricius. Fauna Greenland ica, p. 324. 



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