LINEUS MARINUS. 181 



probably for protection and a proper supply of food. In the same way the Tetrastemma before 

 mentioned frequents the branchial chambers of the Ascidians, the Planaria angulata of Agassiz 

 (not Miiller) the under surface of Zimulus, and the Planaria the cavities of the Medusas ; or, as 

 Harmothoe imbricata, Polynoe areolata, and others, live in harmony with Chcetopterus norvegicus 

 in its tube, and Polynoe scolqpendrina with Marphysa sanguinea and Terebella nebulosa in their 

 tunnels. 



Prof, van Beneden, however, correctly indicates its affinity with the Prorhynchus stagnalis of 

 Max Schultze, a freshwater species, and gives an interesting if not strictly accurate account of its 

 development. 



Sub- Order— ANOFLA. 

 Proboscis without stylets. 



Family II. — Lineid^e. 

 Genus V. — Lineus, 1 Sowerby, 1806. 



The typical species of this genus was one of the first Nemerteans known to~ science, viz. 

 the Gordius marinus of Montagu. The generic name employed by the latter, however, as he 

 himself was well aware, could not stand ; and while he was waiting till the discovery of other 

 species would enable him to give a more comprehensive description of the genus, Sowerby 

 published ' The British Miscellany/ in which the generic name above mentioned was bestowed on 

 the same characteristic species. 



Generic character. — Body more or less elongated, rounded or somewhat flattened, and 

 tapered posteriorly. Head distinct, spathulate, and generally truncate in front. Eyes numerous, 

 arranged along the sides of the snout anteriorly ; rarely absent. Mouth in the form of a con- 

 spicuous longitudinal slit on the ventral surface. Other characters as in the family. 



1. Lineus marinus, Montagu. Plate IX; and Plate XVIII, figs. 1 — 3. 



Specific character. — Eyes numerous, deeply set in a marginal row on each side of the snout. 

 Of a blackish or very dark olive colour, more or less distinctly streaked longitudinally. Body 

 rather rounded. 



Synonyms. 



1758. Sea-Long Worm, Borlase. Nat. Hist. Cornwall, p. 255, tab. 26, f. 13. 



1804, Gordius marinus, Montagu. Linn. Trans., vol. vii, p. 72. 



1806. Lineus longissimus, T. W. Simmons. Sowerby's Brit. Misc., p. 15, pi. 8. 



1 Linea, a line. 



