292 CEYLON PEARL OYSTER REPORT. 



The tube is pergamentaceous, finely fibrous, thinly encrusted with mud and calcareous 

 minutiae. The posterior notopodia adhered firmly to the inner wall of the tube and 

 were greatly elongated. 



Phyllochaetopterus herdmani (Hornell) Plate V., figs. 127 to 132. 



Spioclwlopterus herdmani, Hornell, ' Ceylon Pearl Oyster Report,' Part I., 1903, p. 16. 



Locality : Galle shore, under stones. 



Narrow cylindrical tubes encrusted with relatively coarse sand-grains and hard 

 fragments of all kinds, including Foraminifera. The worms outside their tubes are 

 soft and convoluted, and the hinder poi'tion of the body is very fragile. The three 

 regions of the body behind the buccal region are the thoracic region, with ten (in one 

 case nine) setigerous segments ; the branchial region, consisting of two segments ; 

 finally the abdominal region with as many as 40 to 50 segments. The ventral w r all 

 of the thoracic segments is thickened to form a large glandular cushion, and the 

 lateral wall of each abdominal segment is marked by a long narrow brown tract 

 between the dorsal and ventral divisions of the parapodium on each side ; sometimes 

 this pigment tract is very dark. Above its dorsal end occurs the clavate notopodium, 

 and below its ventral end the neuropodium, subdivided into two narrow uncinigerous 

 lobes. The head is surrounded by an incomplete collar, open dorsally (Plate V., 

 fig. 127) ; above and behind the dorsal ends of the collar occurs the second pair of 

 tentacles, supported by a bundle of three long delicate internal setae. The long 

 s})irally coiled tentacles of the first pair are inserted immediately in front of the 

 second pair, and are still retained in some of the specimens. 



The first parapodium contains about twenty spatulate or vane-tipped setae, arranged 

 in general in a single row, forming a dorsiventral monostich. The length and width 

 of the vane varies ; sometimes it terminates in a point, generally its border is broken 

 up into shreds (Plate V., fig. 131). The second parapodium resembles the first, 

 and so does the third as a rule, but in one specimen there are five modified setae 

 (resembling those which usually occur only in the fourth parapodium) intercalated 

 between the normal spatulate setae (Plate V., fig. 129). The fourth parapodium 

 contains, in addition to the spatulate setae, eight or nine modified flattened setae 

 (Plate V., fig. 128). The remaining thoracic parapodia contain the usual setae. A 

 notopodium from the second branchial segment contains 16 or 17 long internal setae 

 in the inner division of it. The plan of a branchial segment is shown on Plate V., 

 fig. 130. The borders of the notopodium below the distal expanded bifid portion 

 are densely ciliated. The dorsal body-wall of the branchial region appears to be 

 glandular. 



Next to the notopodium comes a gill, a thin membranous expansion folded upon 

 itself in the preserved specimen ; this passes below into a wing-like dermal fold with 

 free surfaces and a thickened outer border, which is the uncinigerous torus. The 

 unciui in a neuropodium of a branchial segment have 9 to 11 denticulations ; when 



