711 MH. L. A. B(mT?.-vDAiLE OS TUB SPAWN [Dec. 17, 



Nymphalid^. 



22. Pybameis cakdui Linn. 



23. Hypolimnas misippus Linn. 



24. Cymatogeamma dominicana Goclm. (A mere fragment.) 



25. Aganjsthos odius- Fabr. 



26. DiOiSTE JUNO Cram. 



Papilionid/e. 



27. B,HABDODB,YAS TRITE Linn. 



28. Phcebis agarithe BoiscL 



29. Aphbissa statira var. Cram. 

 80. Paptlio ptranthfs Cram. 



6. On tlie Spawn and Young of a Polychsete Worm of the 

 Genus Marphysa. By L. A. Borradaile^ M.A. F.Z.S., 

 Lecturer in Natural Sciences at Selwyn College, Cam- 

 bridge. 



[Eeceived July 27, 1901.] 



(Plate XXXIX.^) 



The Jafna district in the extreme north of Ceylon presents a 

 striking contrast to the rest of the island. Instead of the rainy 

 hills of the south central districts, the jungle of the centre, or 

 the swampy plains of the south and west, all equally covered \^'ith 

 luxuriant vegetation, there are here flat, dry, sandy plains of 

 coral-limestone, endowed with the lowest rainfall in the island 

 and bearing a scanty growth of palmyra-palms, Ricinus-hwshes, 

 aloes, and cactus. These plains nre intersected by a system of 

 shallow salt-water lagoons, communicating with tlie sea at three 

 points only — on the west at Jafna, on the east at Chundikulam, 

 and on the north near the little native village of Tondimanar. 



Prom the Tondimanar entrance a lagoon runs southward for 

 some half-dozen miles inland and then breaks into two arms, 

 extending south-east and south-west at an obtuse angle. The 

 western arm finally ends by joining the large expanse of water 

 south-east of Jafna, which, opening to the sea both on the east 

 and on the west, makes the Jafna district an island. The seaward 

 opening at Tondimanar is narrow and is almost closed by a sand- 

 bank at low tide. At high water there is free communication, and 

 the level of the lagoon of course rises and falls with that of the 

 sea, the \\ater running out with a strong current at the ebb. The 

 bottom is of white sandy mud covering darker greyish mud, with 

 patches of weed in parts. The depth at low water is no\^"here 

 more than three feet. 



^ For explanation of the Plate, see p. 720. 



