28 TRAVISIA FORBESII. 



Head a simple pointed cone, somewhat flattened ventrally. 



Body (Plate LXXXVIII, fig. 3) about f in. in length, and consisting of two dis- 

 similar regions, a broader elliptical anterior and a subcylindrical posterior. The former 

 has fourteen segments (though this distinction is more or less arbitrary), which increase 

 gradually in diameter to the middle, and decrease posteriorly. The second segment has 

 one ring, and is devoid of feet. The succeeding have two or three narrow rings, a dorsal 

 tuft of bristles, a branchial filament (cirrus), a circular pore, and a shorter tuft of 

 ventral bristles. The mouth opens on the ventral surface, between the second and third 

 segments, a small groove running forward to the former in well-marked specimens. 



In fine examples from Greenland the anterior runs into the posterior region without 

 evident distinction — other than the gradual disappearance of the rings on the segments. 

 Moreover the entire number of segments seems to be smaller than stated by Dr. Johnston, 

 the total number varying from twenty-five to twenty-seven or twenty-eight. 



The posterior region has about thirteen segments, more boldly marked than in front, 

 and thickened laterally where two short and somewhat lobate papillse occur, a narrow 

 ring being present between each thicker one. A short cirrus arises below the upper 

 papilla near a tuft of bristles. The penultimate segment is small and devoid of bristles. 

 The terminal or anal segment has a cup-like circle of six soft obtuse papillae (Johnston), 

 with the vent in the centre. This region seems to be occasionally mutilated, so that it 

 ends abruptly in a round disc. 



The skin is boldly reticulated throughout ; the isolated granular areas, which are 

 irregularly pentagonal or hexagonal, being separated by pale lines. It rapidly secretes 

 a mucous coating to which sand-grains and other debris adhere. 



In life it is of a uniform, pinkish colour, slightly paler or straw-coloured laterally 

 and posteriorly, and somewhat iridescent on both dorsal and ventral surfaces. The 

 viscera in situ were pinkish, and a coil extruded through a rupture was gamboge-yellow. 

 The branchial cirrus has a streak of red. A distinct, median, ventral blood-vessel is 

 apparent, but no dorsal. Many small, whitish bodies (ova ?) rolled about in the peri- 

 visceral fluid of the posterior segments in August. 



In an example, measuring about 15 mm., from Norway (Dr. Merle Norman's), the 

 entire exterior is enveloped in mucus which clings tenaciously to the surface and is dotted 

 with sand-grains. The posterior or caudal region seemed to have only eight or nine 

 segments. An interesting feature was the occurrence on the posterior border of one of 

 the cirri of a bifid process so that the cirrus truly resembled a gill. 



Considerable variation is met with in the length of the posterior region of the body 

 and in the number of the cirri— to judge from Dr. Johnston's drawing and the figures of 

 Eathke. Those procured have all been small, and instead of having thirteen posterior 

 segments, as Dr. Johnston states, nine or ten are present. The largest examples observed 

 have been procured in Greenland. 



The bristles are comparatively short, simple, slender structures (Plate CIII, fig. 4, 

 and Plate CIV, fig. 8), tapering gradually to a fine point. They are most conspicuous 

 anteriorly and posteriorly. 



Habits.— In captivity it is inert, rolling about on its side, thrusting its snout hither 

 and thither and elongating the anterior and posterior regions to a slight extent. 



