POTTS— POLYCH^TA. 331 



Many of the differences which Grube sets down between P. chrysocoma and P. indiea. 

 appear to be valueless. Such are, for instance, the length of the ventral setae and the 

 condition of the dorsum. 



Localily. Wasin, Zanzibar ; two specimens collected by Mr. C. Ciossland. 



Family PolynoidsB. 



Genus LEFIDONOTVS. 



6. Lepidonotus carinulatus, Grube. 



Pulynoe (Lepidonotus) carinulatus, Grube, Aiinuiata Semperiana, 1878, p. 26. 

 Lepidonotus carinulatus, Willey, iu Herd man, Ceylon Pearl Oyster Report, pt. iv. 190.5, p. 248. 

 Lepidonotus carinutata, Malaquin & Delionie, Annelides d'Amboine, Rev. Suisse da Biol. vol. xv. 

 1907, p. 3i4. 



Measurements. Tlie largest was 9 mm. long and 3 mm. broad, rather smaller than 

 "Willey's specimens. 



Willey has given a full description of the elytra whifh form the distinguishing feature 

 of the species. Tlie papillas of the surface are flattened, spherical in outline save where 

 they come into contact and are polygonal, largest over the centre and smallest toward 

 the margin, where they are markedly keeled. ToAvards the external fringed margin the 

 papilhe are small and echinulate, generally with only two or three spines. In Willey's 

 Singhalese specimens the anterior elytra were very difl'erent, with a " verrucose " 

 appearance due to the great development of spheroidal echinulate papillae. This marked 

 modification does not appear in the present specimens. In one individual the papillae of 

 the centre were not flattened but raised into a rather high tubercular crest, and the 

 papillae in general were larger and rather sparsely scattered. 



Localities. Saya de Malha, C 12, 47 fathoms, with Psammolyce and Pantkalis ; 

 Suvadiva, 26 fatboms ; Fadifolu, 20 fathoms, several. 



This tiny species of Lepidonotus is described as " the most abundant and typical 

 representative of the genus on the Ceylon pearl banks." It appears also to be widely 

 spread in the Indian Ocean. 



7. Lepidonotus trissochcetus, Grube. 



Grube, Annulata Semperiaua, 1878, p. 25. 



Willey, in Herdman, Ceylon Pearl Oyster Report, pt. iv. Polyclijeta, p. 249. 



Measurements. The largest specimen, from S. Mahlos, Maldives, was 20 mm. long and 

 4'5 mm. broad with setae ; no. of segments 26. 



This species is easily distinguished from all others by the two very different kinds of 

 setae in the notopodium. The so-called "hastate" setse of Willey are generally the 

 longest, and are surrounded by a sheath of shorter "spinulose" setae. In the anterior 

 segments there is little difference in length between the two kinds : it is only at the 10th 

 segment that the hastate forms become markedly longer. Willey considers the hastate 



