NEPHTHYS INCISA. 39 



1875. Nephthys incisa, Ehlers. Zeitscli. f. w. Zool., xxv, p. 19. 



1876. „ „ Mcintosh. Proc. Roy. Soc, xxv, p. 216. 



„ „ ingens, Yerrill. U. S. Comm. F. and Fish., p. 583. 



1879. „ incisa ( = ingens, Stimpson), Yerrill. C. List, U. S. Comm. F. and F., p. 7. 



„ Webster. 32nd Rep. N. Y. Mus. Nat. Hist., p. 104. 

 „ „ ingens, idem. Trans. Albany Instit., p. 213. 



1883. „ incisa, Levinsen. Yidensk. Meddel. Foren. Kjoben., p. 217. 



1884. „ „ Webster and Benedict. Ann. Chart. Mass. (from U. S. Rep. F. and F. for 



1881), p. 702. 

 1893. ,, „ Levinsen. Yidensk. Ud. 'Hauchs/ p. 338. 



1900. „ „ Mcintosh. Ann. Nat. Hist., ser. 7, vol. v, p. 262. 



1901. „ „ Whiteaves. Geol. Surv. Canada, No. 72^, p. 83. 



Habitat. — Connemara, Galway, 1871 (A. Gr. Moore). 



Extends to Greenland ('Valorous' Expedition), East American shores (Verrill), 

 Canada; 'Porcupine' Expedition, 1869, 6—80 fathoms; 'Porcupine,' 1870, nine miles 

 off Cape Finisterre, 81 fathoms. 



Head (Plate LVII, figs. 19 and 20) somewhat shield-shaped, nearly of the same 

 breadth from front to back, though it is a little wider in the middle ; marked by two pale 

 lateral areas, which map out the surface. Anterior and ventrolateral tentacles small 

 and conical. 



The mouth (Plate LVII, fig. 20) has a short filament towards the anterior part of 

 each lip. 



Proboscis with twenty-two rows of minute papilla?. A short median cirrus occurs 

 in the smooth distal region both dorsally and ventrally (Malmgren). 



The species is characterised by the dark brown bristles, the slight development of 

 the lamellae, and the wide space between dorsal and ventral divisions. The typical foot 

 (Plate LXVII, fig. 4) presents in the anterior region of the body a rounded dorsal 

 lamella, as in JSf. longisetosa, (Erst., though it has a different shape, is smaller, and 

 extends nearly to the tip, whereas the lobe in the latter does not. At the tip of the 

 foot and placed behind the former is the small leaf-like dorsal cirrus, acute at the tip, 

 and separated only by a shallow notch from the somewhat massive short branchia, 

 which is coiled with the tip outward and forward. The two processes (cirrus and 

 branchia) move freely together, and are separated from the dorsal lamella. The 

 spinigerous region is comparatively small, and is hidden between the rows of bristles. 

 The fillet guarding the base of the barred bristles is developed into a considerable free 

 flap superiorly and inferiority, so that it and the dorsal lamella hold the bristles between 

 them. 



The inferior division presents a somewhat trifid condition, the posterior flap 

 or lobe projecting sufficiently to guard the bases of the bristles, while the fillet 

 in front is better developed and projects more superiorly. The conical spinigerous 

 region is thus guarded by the rows of bristles and the flaps. The ventral cirrus is 

 small and conical. 



In the middle of the body the branchia becomes a short and slender process directed 



