52 LAGIS KORENI. 



cirrus or tentacle is crenulate, with a broad base, which tapers by-and-by to a long- 

 slender process with a slightly bulbous tip. In structure this shows externally the 

 cuticle and hypoderm with fibrillation, whilst internally it has granules of various 

 sizes — probably hypodermic. It may be penetrated by the perivisceral fluid. In 

 life this and the anterior cirrus or tentacle move a little to and fro, or the tips are 

 coiled and waved. When the animal is killed in formaline the pharynx (proboscis) 

 occasionally protrudes as a dark mass at the upper and median region of the tentacles 

 (Arnold Watson). 



An interesting feature in the oral region is the presence of the nuchal organs, as 

 demonstrated by Arnold Watson (Plate OXXXVI, fig. 21). These are frilled or folded 

 organs with dark-brown edges situated on each side of the pale tentacles, lying, as it were, 

 midway between these and the large papilla posterior to the long lateral cirrus. " The 

 anterior and posterior lobes of the organ are directed (when viewed from the ventral 

 surface) upward so as more or less to face each other, and the small lateral (inner) lobes 

 are also bent upward " (Arnold Watson). Considerable variation occurs in the appearance 

 from the simple condition in which they form erect plates with ventral face to ventral 

 face to the complicated structure. The lateral lobes are only found on the inner side, 

 i. e. nearest the mouth, not at both sides of the organ. The margin of the lobes is 

 generally rounded, swollen, and varies in colour from dark grey to dark brown in contrast 

 with the opaque or sometimes semitransparent white of the rest of the organ, which is 

 always exposed — that is, above the general surface (Watson). 



The tentacles form a dense mass, each marked by a longitudinal groove, the red 

 blood-vessel running in the middle line, the blood now flowing distally and again proxi- 

 mally in the same vessel. They are mobile organs, and undergo constant contractions 

 and elongations, the tip being often clavate or spatulate. The grooved surface of the 

 tentacle is minutely tuberculated toward the tip, probably in connection with its tactile 

 functions in building the tube ; indeed such may perform the part of minute suckers. 

 The blood seems to flow to the tip of the organ, which becomes deep red, remains there 

 for a little, and then is sent backward. A single blood-vessel apparently with similar 

 action occurs in the long cirri. 



The body is from 1\ to 2 inches in length, gently tapered to a comparatively broad tail, 

 which has the anal appendix passing off at an angle posteriorly. It is rounded dorsally, 

 flattened and somewhat grooved ventrally, whilst laterally are, from (front to rear, the 

 branchias immediately behind the long cirrus, a segment without bristles, and fifteen 

 bristle-tufts with lamella? for the hooks from the fourth bristle-tuft backward, or twelve 

 in all. 



The general hue of the dorsum is brownish pink, the dorsal blood-vessel and the gills 

 being deep red. The first three body-segments have numerous brown specks (eyes ?) on 

 their posterior edges. The tentacles are dull pinkish in mass. The caudal process is 

 slightly yellowish. The intestine shines through the translucent iridescent skin as pale 

 brownish, and a large blood-vessel is attached to it dorsally, below the more slender median 

 dorsal trunk. This large trunk appears to end in the deep opaque reddish mass below 

 the median fillet of the second bristled segment. The median dorsal (superficial) trunk 

 commences at the tail, whereas the larger and deeper trunk on the gut appears about the 



