90 Prop. Mcintosh's Notes from the 



aufl more flattened toward the base. They are hard, though 

 somewhat brittle, and the edge ol! the razor is often notched 

 in making the sections. 



The dorsal or anterior edge above the paleolje is smooth, 

 firm, and somewhat hollow, with a marginal rim which 

 forms more than a semicircle externally, and ends in a 

 subulate tentacle ventrally. A notch separates the latter 

 from the veil or frilled membrane to the ventral surface of 

 the paleolse, and the edges of the muscular membrane bear 

 a series of long papillae or fimbriae. This membrane is not 

 attached directly to the ventral edge of the rows of paleolae, 

 a firm transversely elongated area occurring at their hase. 



Below and attached to the foregoing veil is a dense series 

 of tentacles on each side of the mouth, which has a dorsal 

 fold in the middle line and a transverse one behind it. In 

 the median line ventrally is a large central boss, and on each 

 side is a fillet continued vipward by a ridge to the long lateral 

 cirrus in front of the branchiae. The cirrus is crenulate, 

 with a broad base which tapers by and by to a long shaukr 

 process with a slightly bulbous tip. In strncture tiiis shows 

 externally the cuticle and hypoderm with fibrillation, whilst 

 internally it has granules of various sizes — probably hypo- 

 dermic. 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. 



AViien withdrawing itself into the tnbe the two rows 

 of golden bristles slightly and symmetrically overlap, for 

 they can both be separated and approximated, and the firm 

 smooth area adjoining forms a platform, the whole per- 

 forming the part of an operculum. 



The tentacles constitute a dense mass, each marked by a 

 longitudinal groove, the red l)lood-vcssel running in the middle 

 line, the blood now flo\^ing distally and again proximally 

 in the same vessel. They are mobile organs and undeigo 

 constant contractions and elongations, the tip being otten 

 clavate or spathulate. The grooved surface of the tentacle 

 is minutely tubercnlated toward the tip, probably in con- 

 nection wiih its functions in building the tube — indeed, such 

 elevations may [)crlbrm the [)art of minute suckers. The blood 

 seems to How to the tip of the organ, which becomes deep red, 

 remains there for a little, and then is sent bac-kwarcl. A 

 single blood-vessel apparently with similar action occurs in 

 the long cirri. 



The body is from 1-^ to 2 in. in length, gently tapered to 

 a comparatively broad tail, which has tlie anal ap])en(lix 

 passing oH' at an angle postorioily. It i^ rounded dorsally. 



