Gatty Marine Lahoratory^ St. Andreios. 171 



bristles, then a slight constriction takes place at the level of the 

 cnticle, the tip being broad and more or less striated, but ter- 

 minating in a long hair-like process. The perfect crotchet 

 or hook is best seen in the posterior region of about fifteen 

 segments, the shaft dilating a little from the soft base up- 

 ward, then narrows about the level of the skin, from which 

 a noticeable forward bend occurs, the long stout tip ending 

 in a blunt point. The whole organ is striated to the point 

 and somewhat resembles a miniature scalpel which has a 

 curve backward (PI. VII. fig. 11). The direction of these 

 crotchets is at first slightly backward, but by- and- by they 

 project transversely outward, and in four or five of the 

 terminal segments they are directed forward — doubtless in 

 connexion with their functions in mud or sandy mud. 



Cirratulus norvegicus ? 



A form dredged off Drobak, Christiania Fjord, in 30-100 

 fathoms, in 1879, somewhat resembles Cirratulus tessellatus in 

 so far as the dorsal divisions of the anterior feet approach 

 each other dorsally, and in some are raised, so that the spaces 

 between the lateral lines at the base of the feet are narrow in 

 front and gradually widen in their course backward. More- 

 over, a considerable amount of dark pigment characterizes 

 the anterior dorsal region and also occurs along the poste- 

 rior lip of the gaping mouth. 



The head has the form of a small blunt cone, sometimes 

 constricted posteriorly, and when the button-shaped proboscis 

 is extruded, as in the majority of the specimens, it projects 

 upward and forward, or, in complete extrusion, upward. 



The body is probably between 1 and 2 inches in length, 

 flattened anteriorly, and somewhat rounded posteriorly. It 

 is tapered rather abruptly anteriorly, but does not appear to 

 be much tapered posteriorly, only a slight diminution taking 

 place in the preparation ; but such may be an incomplete 

 specimen. It terminates posteriorly in a pouting button- 

 shaped vent, which is produced ventrally into a process with 

 a median fissure and a fillet on each side of it (PI. VII. fig. 12) . 

 The veutral surface is flattened, sometimes with a median 

 ridge and two lateral elevations, though in a few neither is 

 visible. The buccal and two achsetous segments follow the 

 head, and in one example each has a dorso-lateral frill, it 

 may be from imperfect preservation. Every example presents 

 two short lappets (or, it may be, the bases of tentacles) 

 interposed between the converging lateral lines of the feet 

 nearly opposite the first bristle-bundles. A series of long 



