438 A. E. Merrill — Marbie Nemerteans of New England^ etc. 



CerebratuluS fuSCUS (Fabr.) Venill. 



Planariafusca Fiihw, Fauua Groulandica, p. :{2'l, 1780. 



Meckelia olivacea Rathke, Beitrage zur Fauna Norvvegeus, p. 324, 1843 (from Acta 



Akad. Ca3S. Leop. Carol. Nat. Cur., vol. xx, 1843). 

 Serpentaria fragilis G-oodsir, Aim. Nat. Hist., vol. xv, p. 387, pi. 20, tigs. 1 and 2, 



1845. 

 Jieckelia se7-2>e7ita'na Diesiug,Syste\na lielm., vol. i, p. 266, 1850. 

 Gordius fragilib- Dalyell, Povk^. Great., vol. ii, p. 55, pis. 0, 7, and 7 (his), 1853. 

 Meckelia serpentaria Leuck-Avi, Arcliiv. fur Naturges., ii, p. 187, 1859. 

 Serpentaria fragilis Johnston, Catalogue Brit. Mus., p 28, 1865. 

 CerebratuluS angulatus Mcintosh, British Annelids, part i, Neraerteans, p. 195, 1873. 

 Cerebratulus (?) sp. undeter. («) Verrill, Report on Invert. Anim. of Vineyard Sound, 



p. 336 [630], 1874. 

 Cerebralulus fragilis (!) Janseu, op. cit., p. 85, 1878. 

 Cerebrniuhis grandis (Sars) Jensen, op. cit., p.. 97, pi. 8, figs. 17-22. 

 Cerchratulas fusce.sceus Levinsen, Bidrag til kuudskab om Groulands Turbellarie- 



fauna, p. 40 [202], 1879. 



PLATE X.XXVII, Kl<;URES 2 TO 2c. 



Body large, stout, rounded for a considerable distance back of the 

 head, and thence broad and much flattened to the posterior end, the 

 edges thin and usually pale in color. Head very changeable in 

 form, often broad lance-shaped, with acute snout, changing (piickly 

 to ovate, rounded,' or even emarginate forms. Ocelli wanting. 

 Mouth large, oblong. Cephalic slits large and deep, moderately 

 long ; they do not meet in front, nor run into the proboscis-})Ore, 

 but lie in a higher i)lane Anal cirrus slender, easily detached. 



Color, above, dull ash-gra}^, greenish gray, slate-color, clay-color, 

 o-rayish olive, or dirty brown, paler below, and with paler margins, 

 within which, on each side, a red line, showing through theintegumeut? 

 marks the position of the large lateral nerves. Sometimes the back is 

 mottled with lighter, and darker gray or slate ; mouth surrounded by 

 white, reddish at the anterior angle. 



Length np to two feet or more. A specimen taken at Todd's 

 Head, Eastport, Me., under stones at low-water, Aug. 19, 1870, 

 measured 400'"'" in length, when moderately extended ; breadth, in 

 middle, 12 to 14'"'", but it could contract to less than 100'""' in 

 length. 



This is a northern and arctic species. I have taken it at Halifax, 

 ]^. S.; Grand Menan, N. B,; Eastport, Me., under stones and in 

 sand and gravel near low water mark, and beyond in shallow water 

 to 20 fathoms or more. South of Cape Cod it occurs in 15 to 45 

 fathoms on bottoms of sand and mud in the cold areas swept by the 



