40 Prof. M'lntosh's Notes frov} the 



appendages is distinct in some preparations. Tlie brancliite 

 are coiled, tlie ))osterior small tentacles filiform, vvlulst the 

 larger are clavate and grooved. The month opens iu the 

 centre above a line joining the attachments of the trans- 

 lucent lateral flaps, and in a groove between the two 

 in'oniinent anterior bosses. 



The body is Terebcllilorm in appearance, about an inch 

 in length, enlarged anteriorly, and tapered posteriorly to 

 terminate in an anus with two cirri. It is rounded dorsally, 

 grooved ventrally, and has about seventy segments. The 

 mouth opens anteriorly at the furrow between the bosses, 

 the translucent lateral flaps curving inward to be attached 

 on each side. Ventrally is the tumid and streaked lower 

 lip which forms the conspicuously truncated anterior end. 

 The grooves generally show a symmetrical arrangement, a 

 broad median belt passing down the centre, flanked by two 

 or three stripes on each side, the ventral ends being split. 

 The second segment forms a continuous ring dorsally and 

 ventrally, and sometimes projects forward dorsalh^, so as to 

 ensheath the i)osterior cephalic e<\ge and the eyes. It bears 

 dorsally the first branchia on each side, a single thick and 

 proportionally long filament tapered distally — distinguished 

 by the bright red central vessel and often by the spiral con- 

 dition. The third and fourth segments also bear a pair of 

 gills, which readily fall off in the preparations. 



'Jhe sl;ort setigerous processes, which have oblique tips, 

 commence on the sixth segment and are fifteen in number. 

 Each tuft has two scries, a longer and a shorter. The longer 

 bristles are pale golden, one half free and one half inserted 

 in the tissues, the shafts dilating a little fi*om the base, then 

 remaining cylindrical till the commencement of the very 

 narrow wings, which have minute strife directed ontward and 

 upward, after which they taper to a fine hair-like curved tip. 

 They thus apjicar to represent the first stage of the develop- 

 ment of wings on a bristle. The bristles slope outward and 

 backward in the preparations, but are directed forward in 

 life, the convexity of the terminal curve being in the same 

 direction ; the shorter forms often alternate with the longer, 

 and their number corresponds nearly with that of the longer, 

 viz., six in each tuft. There is also a slight gradation in the 

 size of the longer bristles from the dorsal to the ventral 

 edge. 



Jielow each bristle-tuft is a row of hooks with elongated 

 curved shafts, which increase from the base upward to the 

 shoulder — above which the neck is distinctly narrowed, the 

 head again expanding so as to resemble with the main fang 



