92 Prof. M'Intosli's Notes from the 



capillary bristles, which have a nearly cylindrical shaft and a 

 tapered tip with well-marked wings, and a few slender trans- 

 Incent forms Avhich taper terminally without traces of wings 

 (the anterior of Arwidsson). The hooks, which commence 

 on the fifth bristled segment, are distinguished by their great 

 size, the length and curvature of the shaft, which gradually 

 dilates from the base to the slight shoulder from which the 

 long, straight, distal region or neck curves off, and as it 

 again dilates a little distally, it is narrowest in the middle. 

 The great fang passes off at more than a right angle, and a 

 knob occurs on the throat immediately below, whilst on the 

 crown above it are five teeth, though they are not always 

 visible. The gular bristles arise at the base of the great fang 

 and the sides of the knob, and slope, or rather curve, forward 

 and upward. The centre of the shaft is longitudinally 

 striated, and the upper part of the neck is boldly striated 

 obliquely, the striae in the middle and lower part of the neck 

 being less oblique. Little difference is noticeable in the 

 structure of the hooks, though in the first series one or two 

 may be imperfect. 



Arwidsson describes the tube as formed either of fine sand, 

 or of shell-fragments, fragments of Echinus spines, Foranii- 

 nifera, and larger sand-grains. 



The fourth species is Pseudochjmene cprstedi (?), Claparede, 

 which De St. Joseph considered to be the Clymene d'lgitata 

 of Grube. It was procured in sandy tubes under stones at 

 Guernsey and Herm. In this the cephalic plate is somewhat 

 like that of PraxilleUa, with a conical median frontal process, 

 slightly marked lateral notches, and median posterior notch. 

 The rim of the plate is moderately developed, and its outline 

 is elliptical, more elongated antero-posteriorly than any 

 form hitherto observed in Britain, a feature partly due to 

 the continuation of the narrow anterior border into the 

 median frontal process. When the proboscis is included the 

 surface is slightly convex, but when the organ is extruded it 

 is somewhat hollow. The keel is long and well-marked, 

 commencing a little in front of the posterior rim and running 

 forward to the base of the median process. The nuchal 

 grooves appear to go along the whole length of the keel and 

 to pass outward anteriorly on each side of the median 

 process. The arrangement thus differs from that in Psendo- 

 clymene, which has very short nuchal grooves. The slightly 

 marked lateral and median posterior notches of the rim, as 

 well as the fusion of the outline of the median frontal process 



