POLYCH^ETA. 307 



Branchiomma quadrioculatum, n. sp. Plate VII., figs. 168 and 169. 



Locality : Aripu Coral Reef. One specimen, apparently incomplete behind, 

 48 segments. 



Thorax 4 - 5 millims. long, 2 millims wide. Abdomen 13 millims. long. Eight 

 thoracic segments. Gills 6 millims. long, banded with three or four purplish vittse ; 

 14 radioles in each. Collar with median incisura ventralis, a deep median dorsal 

 notch and a still deeper submedian dorsal notch on each side. The four most dorsally 

 placed gill-rays carry subterminal eyes, of which the dorsal pair are larger than the 

 subdorsal pair (Plate VII., fig. 168). Seen from below, pressing the gills aside, 

 laciniaj buccales are brought into view, including a flattened median tongue which 

 rises up straight between and below the antennas, and on either side of it an arcuate 

 membranous fold. The buccal seta? are normal, capillary, limbate ; thoracic setae 

 normal limbate and subspatulate ; thoracic uncini biserial, an anterior row of cuspidate 

 uncini "' and a posterior row of avicular uncini (Plate VII., fig. 169). Abdominal 

 seta? 15, limbate; abdominal uncini uniserial, avicular. 



Hypsicomus phaeotaenia (Schmarda). 



Sabella phaeotaenia, Schmarda, ii., 1861, p. 35. 



Hypsicomus phaeotaenia, Marenzeller, ' Siidjapan. Ann.,' ii., 1884, p. 16 of reprint, p. 212 of 



the 'Wiener Denkschr.' 

 Sabella pyrrhogaster, Grube, 'Ann. Semp.,' 1878, p. 250. 



Localities: Station V., off Chilaw, Gulf of Manaar, 11 fathoms, several specimens; 

 and South-west Cheval Paar. 



Marenzeller notes the resemblance between Sabella pyrrhogaster and Hypsicomus 

 phcBOtcmia, but adds that in the former only one kind of setae was observed by 

 Grube in the thoracic tori. According to Grube also the dorsal setigerous lobes of 

 the thorax only contain paleae, whereas in phaeotamia there are a few lanceolate setas 

 in addition to the paleas. The latter discrepancy is easily accounted for by the fact 

 that the lanceolate setae are frequently broken and hence cannot be observed. The 

 former discrepancy with respect to the tori in which the armature is biserial and 

 dimorphic in phceotcenia and alleged to be uniserial and uniform in pyrrhogaster, is 

 undoubtedly due to the circumstance that the row of cuspidate uncini was overlooked. 

 Neither does Grube mention the branchial eyes, the pigment of which was perhaps 

 dissolved out of his material. This species has also been described by Grube as 

 Sabella fuscotcmiata in 'P. Zool. Soc, London,' 1874, p. 328. 



A small though complete specimen measures 25 millims. long without the branchiae, 



which add another 8 millims. From the posterior end of the basal lamella to the 



anterior border of the interfilar membrane or web measures 3 - 5 millims. The eyes 



occur on each side of the distal portions of the gill-stems, 14 to 17 in number, not in 



pairs. The terminal filament of the gill-stem is long, somewhat flattened and tapering 



to a point. 



* " Soies en pioche " ; " Piekelborsten." 



2 R 2 



