BY WILLIAM A. HASWELL, M.A., B.SC. 661 



The tube assumes a variety of shapes according to the form of 

 the object to which it is adherent ; it is always thin-walled, with 

 slight, irregularly placed, ring-like thickenings ; in transverse 

 section it is almost perfectly circular. The proximal portion of 

 the tube, which is usually the part which is adherent, is very 

 slender, and nearly always much curved and may be coiled into 

 a short spiral. The diameter increases distally till at the 

 mouth it is about ^th of an inch. The tree part of the tube is 

 only very gently sinuous. The total length may be as much, as 

 an inch and a half, but is usually less. 



The ordinary length of the annelid is about half an inch. The 

 thorax, which is considerably shorter than the rest of the body, 

 contains seven segments ; it bears very wide lateral flaps and 

 prominent parapodia with long setae. The setae of the first 

 segment (pi. XXXIII., figs. 4 and 5) differ from the rest (pi. 

 XXXIIL, fig. 6.) 



The ventral tori are -0075 to -0150 of an inch in length, each is 

 composed of about twenty to thirty-five pectines, about -001 inch 

 in length and having six or sometimes seven teeth (pi. XXXIIL, 

 fig. 3.) The abdomen contains forty to forty-five segments with 

 long setae, and ends in a pair of short rounded anal processes. 



The branchiae (pi. XXXI., fig. 4), which are twenty in 

 number, have long slender stems beautifully ornamented with 

 lines of white, crimson, red and brown, the arrangement of 

 which is subject to great variation. The operculum (pi. 

 XXXII., figs. 11 and 12 and pi. XXXIIL, figs. 1 and 2) 

 has a very long and slender cylindrical stem reaching far 

 beyond the extremity of the branchiae and more than half 

 the length of the whole body. It is uniform in diameter to 

 near the base of the operculum, where it gradually enlarges to 

 form the basal portion of the latter. The operculum is composed 

 of two segments the proximal formed by the expansion of the 

 extremity of the peduncle to form a wine-glass-shaped body the 

 rim of which is divided into lobes or teeth. The number and 

 size of these lobes or teeth varies to some extent according to the 

 age of the specimen or of the operculum. In young opercula 



