344 DK. H. LYSTER JAMESON ON 



decalcified and mounted entire in Canada Balsam, In none of 

 these could I find Cestode nuclei. 



The example mounted as a slide was a pearl about 2 mm. in 

 diameter, of oval shape, fi-om the Isle of Pines. It had two 

 pseiido-nuclei, side by side, both composed of columnar substance, 

 concentrically laminated. One measured '5 mm., the other 

 •3 mm. This pearl was subsequently sectioned, and no foreign 

 matter could hd detected in the nuclei. I decalcified and examined 

 the other four pearls. The characters of three of them were 

 nearest to those of the pearls in Dr. Kelaart's collection in the 

 British Museum described above, but one had seveial centres, 

 which were surrounded by columnar substance. The fovirth had 

 a little brown body about "2 mm, in diameter, which sections 

 showed to be composed of unrecognisable granular matter 

 surrounded by amorphous substance. No Cestode characters could 

 be identified in it. 



M. Seurat also sent me five slides, with sections of pearls from 

 31. vulgaris fromNew Caledonia, which had been mounted in paraffin 

 wax, but had not been stained or made into finished preparations. 

 I stained and completed these, and found that they comprised 

 about seven ])earls, in all of which, so fai" as could be determined 

 (for the series were not complete), the pseudo-nuclei were either 

 simple cavities containing a few granules or strands of conchyolin- 

 like matter, or masses of concentiically deposited, stratified 

 columnar substance. There was no trace of anything that I could 

 accept as a Cestode. 



M. Seurat stated (37), p. 24, that these pearls had for nuclei 

 Cestode larvae, but I am unable to confirm this. In a recent 

 letter he has informed me that this assertion was based on the 

 appearance of the nucleus of a decalcified pearl, which was not, 

 apparently, examined in section. 



J. Pearl from M. vulgaris /ro«i Nossi-Be, Madagascar. 



M. Setirat also sent me an unmounted slide with sections of a 

 pearl from this species from Nossi-Be, The centre of this pearl 

 was a mass of concentrically deposited cohimnar substance, 

 0"35 mm, in diameter, containing a cavity about 0*1 mm. in 

 diameter. 



K. Pearls from the Lapi Shell (M. vulgaris), /rom the 

 Trobriand Islands, Papua. 



Prof, W. E. Dunstan, F.R.S., Director of the Imperial 

 Institute, very kindly allowed me to decalcify and examine two 

 pearls from this locality, which were taken from among those on 

 exhibit in the Papua Court at the Imperial Institute. These 

 specimens had recently been sent home, by direction of the 

 Administrator, the Hon. M. Staniforth Smith, 



The pearl-banks occur on the western side of Kiiiwina Island, 



