LEIOCHONE JOHNSTONI. 319 



margin of the funnel — the longest being ventral, and two shorter on each side, the 

 mid-dorsal region being bare. 



3. Leiochone Johnstoni, 1 n.s. Plate C, fig. 19— head; Plate CVIII, figs. 7 to 7 c — 



bristles and hooks. 



Specific Characters. — Cephalic region devoid of a dorsal plate, as in L. ebiensis, the 

 median ridge with the nuchal grooves running straight forward to a fillet on each side 

 of the median frontal process, which is less acute than in the species named. A ridge on 

 each side of the median converts the nuchal grooves into deep pits. Body 5 to 6 inches 

 in length and robust. The first segment is short, those in the middle of the body are 

 longer, but no specimen is complete. Bristle-tufts and ridges for hooks are conspicuous. 

 Posteriorly four segments, counting the swollen ring, are naked, and the anal segment, 

 narrower than that in front, has a mid-ventral cirrus longer than the others, and 

 adjoining it are two or three shorter cirri on each side. About half the circumference 

 of the ring is thus bare, the margin being finely crenate. Only a single segment 

 intervenes between the last bristled segment and the anal rim. Bristles in two groups, 

 a stronger-winged series, and a shorter, slender group, with hair-like tips. Hooks with 

 remarkably broad crowns in proportion to the length of the neck, and the crown is 

 flattened in side view and has more than seven teeth above the main fang, which has the 

 gular bristles closely applied to its lower edge. 



Tube composed of coarse sand, firm, but friable. 



Habitat. — Dredged by Dr. Assheton in Loch Alsh and Loch Broom, September, 191J . 



The cephalic region (Plate C, fig. 19) dorsally has no plate, only the median ridge 

 with the deep nuchal grooves, and these run straight forward to a fillet (in the 

 preparation) on each side of the base of the median frontal process which is less pointed 

 than in Glymene ebiensis, in which also a ridge occurs on each side of the median one, 

 so that the nuchal grooves lie in a deep pit which ends bluntly at the median frontal 

 process. No eyes are visible. The body seems to be of considerable proportional size 

 and probably attains a length of 5 or 6 inches, at least. The first segment is short, 

 but those in the middle of the body are longer, though, as no specimen is complete, this 

 is uncertain. Both bristle-tufts and hook-ridges are conspicuous. 



Five segments posteriorly are devoid of bristles, and the anal ring, which is narrower 

 than that in front, has a mid-ventral cirrus longer than the others, and adjoining it a pair 

 of shorter cirri on each side. About half the circumference is thus smooth, or only with 

 a finely crenate margin. In another example with a tail in process of reproduction 

 there were three lateral cirri on each side of the longer mid- ventral, and it is interesting 

 that only a single segment intervened between the anal rim and the last bristled segment. 

 None of the cirri are long. 



The bristles form two groups, a stronger series (Plate CVIII, fig. 7) with stout, 

 striated shafts and distinct wings, and a more slender series (fig. 7 a) with long, hair-like 

 tips, which have a distinct curve. 



The hooks are remarkable for the great breadth of the crown (Plate CVIII, figs. 

 1 Named after Dr. George Johnston, who was the pioneer of Annelidan work in Britain. 



