28 NEPHTHYS HYSTBICIS. 



fathoms ; 422 fathoms ; off Ireland. From various stations in the Mediterranean 

 during the 'Porcupine' Expedition of 1870; 9 miles off Cape Finisterre; 81 fathoms 

 east of Cape de Gatte, 6 miles from shore, 60 — 160 fathoms; Stations 6 and 8, 

 1870. Dredged in the ' Porcupine ' Expedition of 1870, Bono Bay, 25 fathoms ; No. 36, 

 128 fathoms, 1870; No. 2, 305 fathoms, and off Cape Sagres, 45 fathoms; Sidi 

 Ferrara? 45 fathoms. 'Knight Errant,' August 24th, 1882, Station 18, 516 fathoms. 

 Boyal Irish Academy's Expedition, 1885, Berehaven. A closely allied if not identical 

 form was obtained by Canon Norman in Lervig Bay, Norway, in 1878, in considerable 

 numbers. 



Head (Plate LVII, fig. 8) elongated from before backward, with rather pointed 

 anterior tentacles, the second pair being a little behind and ventro -lateral in position. 

 Posteriorly the head is bounded by the collar with a median notch, and a four rayed 

 mark is situated on the head a little in front. 



The peristomial segment shows two broad lips anteriorly and a symmetrical series 

 of furrows posteriorly. The ventral cirrus anteriorly is small, as in A. ciliata. 



In all the Irish specimens the proboscis is ejected, so that the head is distorted 

 (Plate LVII, fig. 8). Its transverse diameter is greater than the antero-posterior. 

 The anterior edge is straight with a small subulate tentacle at each side. A broader 

 ventral one follows after a short interval. 



The body is incomplete in all the examples, but it resembles that of N. ciliata. 



The proboscis (Plate LVII, figs. 8 and 9) is comparatively short with slender bifid 

 papillae in twenty-two rows. The median dorsal pair converge on the long tentacle 

 immediately in front. The rows on each side of the ventral median line converge even 

 in a more marked manner, but there is no long median filament. The papillae are 

 longest distally and diminish backward. Four are distinct and in some is a trace of a 

 fifth, though in the pair on each side of the ventral line there are more (at least six), 

 but they are short. Under the lens the rest of the basal region is smooth. The acute 

 bifid papillae which form a border to the aperture at the tip are very distinct, either 

 projecting prominently or folded over the aperture, the tips crossing in a regular and 

 symmetrical manner. The long dorsal tentacle projects as far as the latter (/. e. to the 

 closed aperture). In some the distal region is pale madder brown. 



The typical foot (Plate LXVI, fig. 10) approaches that of certain varieties of 

 A. Hombergii, such as var. Jcersivalensis, insofar as it has a long, little elevated lobe, 

 which, however, does not pass so far outward or droop so much at the outer end as 

 in - the form mentioned. It stands indeed horizontally. The aspect of the foot also 

 approaches that of A. ciliata, but it differs in minute characters, such as in the form 

 of the dorsal lamella, the condition of the spinigerous region, and other particulars. In 

 front of the capillary bristles the spinigerous region forms a low cone or pyramid of 

 considerable thickness with the spine at the apex, the barred bristles arising in the 

 fissure between it and a large flap or lamella formed by the fillet guarding the bristles 

 (Plate LXVI, fig. 10 a). There is thus an essential difference between it and A. ciliata, 

 in which the spinigerous region itself forms the free flap. The dorsal cirrus is somewhat 

 thick, and is only separated by a shallow notch from the branchia, which is large and 



