iitithj Murine l^'iliorat'jri/, Si. An'./rcia^. 4!) 



tints tlic prominent parts of tlic lip"^, which foi'm a curved 

 frilled bund on each side of" the month. The branchiae arc 

 four on each side, attached to the doisnm of tlie third seg- 

 ment, and two somewhat in front of the other two. They 

 are jjroportionally small tapcM-ing organs siiid (piite snKjoth. 

 It has laterally a |)rocess of the peristomial segment, which 

 also bounds it behind. Ventrally is the mouth, which has a 

 Heshy lip on each side, whilst anteriorly the dorsal surface 

 of these bears the tentacles, which vary much in length 

 iu ditt'erent examples, aj)[)arently from their condition 

 as regards reproduction. The base is the thickest part of 

 each, and it is smooth at first, then the organ tapers to 

 the free end, which is in the preparations somewhat clavate 

 and more finely granular than the rest. The processes or 

 "cilia" gradually increase in length, forming conspicuous 

 organs till witliin a siiort distance of the ti[), which is free 

 from them. Juich is a translucent process of liypodcrm 

 with a cimtral axis or rod, the outline i)rcsenting a slight 

 enlargement at the base and again at the tip, especially in 

 those toward the distal eiul of the series. The translucent 

 liypodcrm of these processes is granular and slightly streaked 

 at the enlarged terminal part, which also occasionally shows 

 I alpocils in the pre[)arations, but Avhether due to the action 

 of the preservative fluid or otherwise is unknown. The 

 axial fibre is structureless and is brittle. 



The function of these peculiarly armed tentacles appears to 

 be of a special character, as the central axis in ea(;h " cilium " 

 shows. The body is elongated, very little narrowed in front, 

 but considerably taperc d posteriorly, where it ends in a tail, 

 having two ciiri of moderate length placed ventrally on each 

 side of an anus, which iu some presents a slightly crcnate 

 margin. The dorsum is smoothly rounded throughout, and 

 the ventral surface is also convex anteriorly, whilst the 

 boldly marked glandular thickening of the segments gives 

 a character to the region, which is nearly co-extensive with 

 the bristled segments, and thereafter a median groove passes 

 backward to the tail. The thickened ventral surfaces of the 

 anterior segments show a slight differentiation of the median 

 line, which, iu contraction, is curved backward and by-and- 

 by is somewhat elevated, and thus is in contrast with the 

 fully extended example. 



The anterior I'cgion has fourteen pairs of setigerous pro- 

 cesses, the first of wiiich is dorsal in position, being situated 

 just external to the branchice of its side, and the next three 

 gradually slope to the side along which the rest lie. Each 

 tuft consists of a series of longer translucent bristles, having 



Ann. tC- .l/(/r/. .V. I/ist. Sor. 8. To/, xv. 1 



