OLIGOCH^TA. 255 



to end freely within the latter, these freely ending processes are 

 anterior, and directed forwards within the fossa, instead of pointing 

 backwards as in other species. 



Atjlophorus palustris, Mchlsn. 



(Plate I., Fig. 5.) 



Several specimens, in the same tube as Limnodrilus socialis and 

 Dero zeylanica. Hill country, Kandy, Ceylon, 1,600 feet. 



The length varied from 3 to 4-o mm. ; but these were all single 

 animals, no chains of two or more being met with ; it appeared 

 however that chains of two animals had existed in the material, 

 but had broken asunder at the budding zone. Breadth, maximum 

 •3 mm. Segments, maximum 52; several of 35 segments; the 

 anterior of two zooids which had broken apart at the budding zone 

 showed 22 segments. 



The prostomium is short and rounded ; the anterior end of the 

 animal is gently swollen, and is thickest at the level of segment IV. ; 

 the thinnest part of the animal is at segments VI .-VII., so that this 

 region has somewhat the appearance of a neck. There are no eyes. 



The hinder end of the animal bears the gills and palps. The 

 palps are a pair of long slender projections from the posterior lip of 

 the branchial funnel ; in length they appear to be about equal to the 

 longest gills ; in breadth they taper gently from a diameter of 60 [x 

 at their base to 16 [ji, at their tip ; the tip is not expanded ; their 

 cavity is not, as is that of the gills, crossed by strands or stellate 

 ceUs. The gills are inserted within the margin of the funnel, which 

 has a complete dorsal lip. There are four pairs of gills, each gill 

 being a sausage- or finger-shaped process, of the same diameter 

 throughout. In breadth they are about 60 ^ ; the length varies, 

 the longest being about '4 mm. ; the most dor sally placed are the 

 shortest, about "08 mm., and arise furthest forward, within the 

 dorsal (anterior) lip of the branchial fumiel. The cavity of each 

 gill is crossed by numerous very regularly arranged strands or 

 partitions , which give it a segmented appearance , as if it were made 

 up of a series of separate chambers ; a nucleus is easily visible in 

 the middle of each strand. The same appearance is seen in sections 

 of a gill cut longitudinally ; m transverse sections however the 

 partition appears as a large single stellate cell. 



The dorsal setae begin on segment V. ; each bmidle consists 

 regularly of one capillary and one needle seta. The capillary seta 

 does not exceed the diameter of the body in length ; the needle seta 

 is about 51-55 ]x long, sickle -shaped, forked at the free extremity, 

 with a slight nodulus at the junction of the curved with the straight 

 portion of the shaft (fig. 5a). 



The ventral setse of segments II.-IV. (fig. 56) differ somewhat 

 from those behind; they are four or five per bundle, 76-84 [jl in 

 length, with the usual double curve and forked extremity ; the 



