170 ALFRED GIBBS BOURNE. 



tents.) They are united at their base witli the palps and 

 more posteriorly with the two most dorsal of the peristomial 

 tentacles. 



The palps are very long, and, springing ventrally, bend over 

 at their free ends towards the dorsal region. They are richly 

 ciliated upon their dorsal surface, and each contains a large 

 blood-vessel, with the green blood nearly filling up its lumen ; 

 they can thus be instantly recognised, as the peristomial ten- 

 tacles have no such blood-vessel, but merely prolongations of 

 the general body cavity. 



The prostomium bears at its sides a pair of black pigment 

 spots (fig. 5, oc), which can be seen through from the ventral 

 surface, and appear at first sight to lie upon the collar, but 

 transverse sections have demonstrated their true position 

 (fig. 5). 



The peristomium, which forms the collar, as stated above, 

 bears two pairs of appendages, each consisting of a very short 

 basal piece and two long rami (noto- and neuropodial), of these 

 the ventral ramus is the longer in each case, but is not so long 

 as a palp. They are all richly ciliated upon their inner faces, 

 and contain prolongations of the general body cavity, but no 

 special blood-vessel. 



The mouth, which is hidden by the collar, lies between the 

 palps and the bases of the prostomial tentacles. 



The somites of the body (counting the peristomial somites 

 as the first) are twelve in number, of these somites 1 — 9 form 

 the "thorax,'' and difi'er from somites 10 — 12 which form the 

 '' abdomen." 



The parapodia are very slightly raised from the surface of 

 the body, and slightly more so in the posterior than in the 

 anterior somites. 



As the peristomum bears no setae the second somite is the 

 first setigerous somite and bears dorsal capillary setse only 

 they are of two varieties placed in two bundles with usually 

 three in each bundle, and resembling respectively figs. 8 and 9, 

 which represent setse from the following somite. The one 

 variety has a very long and delicate blade, while in the other 



