64 



The head forms a small conical flattened process devoid of 

 eyes or appendages. 



Body of variable length, ranging from 135 to 200 m.m., 

 somewhat tetrahedral in form, slightly tapered in front, and more 

 gently posteriorly, but the tail is by no means slender, and it 

 ends in an oblique funnel directed ventrally, with a somewhat 

 frilled margin and a ventral process with three papillae. So 

 frequent is this organ in process of reproduction that it is 

 difficult to say what its precise condition is. In many it is 

 bordered externally by a frhige of the developing and rudimentary 

 feet which resemble papilhe. The latter, indeed, seems to be 

 the normal condition, the frilled lips of the anal funnel being 

 sometimes separated by a smooth margin due to the papillose 

 continuations of the feet. All that can be said of the adult 

 specimens is that the tail ends in an anal funnel, the folds of 

 mucous membrane internally forming six or seven symmetrical 

 plaits on each side, whilst its rim is smooth. The dorsal surface 

 is somewhat hollow, the ventral convex. 



The first segment is acha^tous, and has the mouth on the 

 ventral surface, out of which protrudes the foliaceous mass 

 which gives origin to the name of the genus, and which is 

 is the proboscis, as in allied forms. In partial protrusion three 

 lobes are visible, whilst in full extension there are six or more. 

 The organ forms a complex series of folded lobes the grooves 

 of which converge to the central one. It can be entirely retracted. 



The second segment has dorsally two processes, an inner 

 flattened lamella with a blunt tip, and a tuft of long, slender 

 and nearly straight bristles with closely arranged serrations, 

 springing from its inner side. Externally is a shorter bluntly 

 conical process arising behind a dense row of shorter and 

 stouter bristles, th^ longer showing serrations, the shorter with 

 blunt tips and'only a trace of the serrations, the former lamella 

 pertains to the dorsal region, the latter to the ventral division of 

 the foot. 



At the sixth bristled segment another conical process 

 (branchiae) appears on the inner side of the longer lanceolate 

 leaf and is continued backwards. Whilst the former process 

 remains more or less lanceolate, the outer lobe at (his foot 

 presents a broad lamellar base, which by and by extends 

 downwards as a ridge behind the bristles. 



The arrangement just noted reaches its maximum at the 25th 

 bristled foot ( Plate V., fig. 27 ), which has dorsally and ventrally 

 a somewhat enlarged and tapering inner gill, then the lanceolate 

 lobe and its tuft of long serrated bristles, and, after an interval, 

 a short conical process and the long ridge behind the bristles. 

 The latter consist of a long row of arcirate blunt forms, of 

 others with slender serrated tips, and, ventrally, of elongated 

 serrated intermediate forms. The cjndition resembles that in 

 such forms as Avicia Ciivicri. 



