8 Prof. M'liitosh'rf Notes from the 



series, as iu various groups. Each tuft consists of a longer 

 series with stout, straight, and long shafts, the free portion 

 of which is slightly diminished in diameter toward the 

 com men cement of the winged tip, which is finely tapered 

 and curved. The tips of the bristles are directed upward 

 and backward in their normal condition. Tiie shorter series 

 consists of tiiose with shorter and less tapered winged tips 

 ■which have an accessory terminal blade carried at an angle 

 to that beneath, and is broad at the base and tapered to a 

 slender, slightly curved tip. Such a bristle approaches that 

 of certain Sigalionidse, such as Stheneluis jejfreysii. The 

 structure of these bristles remains the same from the first 

 tuft to the last, but the setigerous processes increase iu 

 prominence in their progress backward. 



No hooks or their homologues occur iu the ridge running 

 downward from the first bristle-tuft, and the ridge itself is 

 intermediate in character. The ridge from the second pair 

 of bristles presents a lateral border and a median linear 

 elevation containing the single row of hooks, the ridge 

 terminating ventrally iu a rounded border at some distance 

 from the ventral shield, the ridges which follow gradually 

 approaching the ventral scutes or shields until, at the eighth, 

 they touch. The third ridge has a double row of hooks, but 

 they appear to be less regular than those which follow. As 

 a rule, the ridges for the hooks are longest in front, and 

 diminish a little toward the twenty-fourth bristle-bundle. 

 Each leaves the setigerous process as a slightly flattened 

 ridge with an anterior, a median, and a posterior fillet, the 

 median bearing the rows of hooks. On the cessation of the 

 bristles the thick and rather long ridge for the hooks 

 increases in prominence and presents a free edge dorsally 

 and viutrally. It diminishes in depth while increasing iu 

 prominence posteriorly. The rows of hooks in life are 

 terminated ventrally by a brownish speck. In the posterior 

 processes the hooks are in a single row. 



The hooks, which commence at the second bristle-tuft and 

 continue to the posterior end, differ from those of A cirrata 

 in the less oblique base, and iu the curves of the anterior 

 outline below the great fang. Usually four teeth occur in 

 lateral view on the crown above the fang, but when examined 

 iu front the crown appears to have several transverse rows. 



The next and third form resembles very closely Amphitrite 

 groenlandica, Malnigren, and is founl both on the British 

 and Canadian shores. The branchiae are slightly branched, 

 and arise by a short stem, which breaks up into a number of 



