290 CEYLON PEARL OYSTER REPORT. 



and gorgeously iridescent setae of the second segment. These are disposed round the 

 head in four bundles ; each bundle may contain up to 10 setae. Grube found only 

 six setae in each bundle. The setae of the third segment are much more slender and 

 shorter than those of the second, but equally numerous, though the number of setae 

 in both these segments varies, probably in many cases through accidental loss. The 

 caudal extremity of the body may be recurved as in Pallasia, as noted by Mr. Watson, 

 but, unlike Pallasia, the segments are all setigerous (Plate VIII., fig. 5). 



Family: MALDANID^. 



This family may be divided into three sub-families : Clymeninas, Rhodininae, and 

 Nicomachinae. For the identification of the worms belonging here it is essential that 

 the whole body should be preserved. There is a fragment of a Nicomachine Maldanid, 

 of which only the six anterior setigerous segments have been preserved, obtained in 

 14 fathoms to the west of the northern end of the Periya Paar at Station LXI. 

 In the absence of the anal segment it is unfortunately impossible to assign it to its 

 proper genus with any certainty. 



Nicomache truncata, n. sp. Plate V., figs. 122 and 123. 



Its head is extremely characteristic, the front vertical with a median crest widening 

 out below into a transverse ridge which overhangs the mouth (Plate V., fig. 123). 

 The peristome is indistinguishably fused with the prostomium, and the two together 

 compose a remarkably short head. This is followed by a short first setigerous segment 

 with the capillary fascicle in the centre ; next a slightly longer segment with the 

 capillary fascicle nearer to the anterior than to the posterior border ; thereafter the 

 segments become elongated, the setae and tori occupying an anterior position in each 

 segment. Below the first and third capillary fascicles there is a large acicular seta ; 

 below the second there are three acicular setae on the left side, one only on the right 

 (Plate V., fig. 122). 



Family : AMMOOHARID^. 



Ammochares orientalis, Grube Plate V., figs. 124 and 125. 

 Grube, 'Ann. Semp.,' 1878, p. 204. 



Station LIV., south of Adam's Bridge, 4 to 40 fathoms. One specimen. 



Total length 28 millims., width 1*5 millims., tapering to less than half this size 

 behind. Length of the laciniate gills, 2 millims. ; length of first segment 2 '5 millims., 

 of second 3 millims., third 375 millims., fourth 3 - 25 millims., fifth 2 - 5 millims. Total 

 number of setigers 22 pairs ; the last eight segments are quite short and were detached 

 from the rest of the body. The first uncinigerous torus occurs below the fourth 

 capillary fascicle. The oesophageal nerve-collar becomes confluent with the ventral 

 nerve-cord in the region between the first and second fascicles (Plate V., fig. 124). 



The first segment is a composite one, comprising three pairs of capillary fascicles 



