Oatty Marine Labor atorij, St. Andrews. 1G3 



2. On Harnaothoc watsoni, 3/'/., un var. II. inarphysic, M'l. 



Whilst stii(lyin<j tlic striu'ture and habits of Lay'ia kormi, 

 Alalingren, lorwartk'd Irora Laurairlfchan, in North Wah^s, 

 Mr. Arnold Watson found a Polyroid as a commeiisal in the 

 tuhe of an adult annelid and he kindly sent it for examina- 

 tion alonj; with some remarks on its eondition in life. It 

 measured about one-fifth of an ineh in length, with white 

 scales bearing reddish-brown markings, whieh at their interior 

 ends joined to form eresc-ents. Anteriorly was a red disk, 

 probably due to the eephalic ganglia. The uu'dian tentacle 

 was long, and one anal cirrus was seen, though most of the 

 dorsal cirri had been shed. 



No scales remained on the body which had a fairly regular 

 outline from the even disposition of the feet. The head is 

 less elongated than iu Hannotlioe inarphysie, and in the 

 preparation retained a pale brownish hue, with the usual 

 median groove enlarging at the anterior peaks. The pre- 

 sence of these anterit)r peaks, whieh the dark pigment at 

 the base of the median tentacle more clearly differentiates, 

 the large size ot the eyes, aud the shorter head distinguish this 

 form from H. marphysa. All the eyes are visible from the 

 dorsum, though the anterior pair, from their slightly lateral 

 positi<Mi, are less distinct than the posterior pair, which lie 

 in front of the nuchal border. The anterior eyes are some- 

 what in front of the middle of the head, and thus separated 

 from the posterior pair by a considerable interval, whilst 

 they are also more distinctly lateral. Both pairs are, how- 

 ever, visible in a lateral as well as in a dorsal view, and all 

 are of meiiium size, considerably larger than those of 

 H. vi(iri)lnjs(e. Tiie median tentacle is long and furnished 

 with elavate papilhe. The lateral tentacles are inferior and 

 in the prej)aration have slightly enlarged or probe-shaped 

 tips. The palpi are of moderate length with tapered 

 extremities, and their surface is smooth. The tentacular 

 cirri are comparatively short and have slender tips, whilst 

 the surface lias a few elavate pa|)illaB. 



Tlie body is normal in shape, and thus (lilfer^ from that 

 of H. marpliyste, being slightly narrowed in front and more 

 distinctly dinunished posteriorly. The number of bristled 

 segments is about thirty. When the scales are removed, a 

 translucent bar, the proboscis, a[)[)ears behind the head. 

 The feet have a legular arrangement from front to rear, ami 

 the j)ali' bristles piojcct beyond them with similar regularity. 

 A typical foot |)rcsents dorsally the cirrus, which is enlarged 

 at the base and tapered distally, with numerous elavate 

 papilla-. The lip of the organ does not project niucli bevond 



