734 



INDEX. 



Pennatulida dredged by H.M.S. "Porcupine." By 

 Dr A. Milnes Marshall, F.R.S., and Dr G. H. 

 Fowler, B.A., 453. 



Plarr (Q.), Docteur es-Sciences. On the Deter- 

 mination of a Curve, on one of the Coordinate 

 Planes, which forms the Outer Limit of the 

 Positions of the Point of Contact of an Ellipsoid 

 which always touches the three Planes of 

 Reference, 465. 



Plates, Colours of Thin. By Lord Rayleigh, 157. 



Platinum, Electrical Resistance of, 190, 195. 



a Redetermination of the Atomic "Weight 



of. By Professor "W. Dittmar, F.R.SS. L. and 

 E., and John M'Arthur, 561. 



Platinum- Hydrogenium, Electromotive Force of, 181. 



Pleuronectes Americanus, Eggs and Larvae of, 117. 



cynoglossus, Eggs and Larva of, 101. 



flesus, Eggs and Larva of, 99, 117. 



limanda, Eggs and Larva of, 100, 117. 



microcephalics, Eggs of, 102. 



platessa, Eggs of, 99, 117. 



Pol 'y acanthus viridiauratus, Ova of, 127. 



Pomatocerus, 673. 



Porcupine (H.M.S.). See Pennatulida. 



Potassium, Chloroplatinate Method for the De- 

 termination of. By Professor W. Dittmar, 

 F.R.SS. L. and E., and John M'Arthur, 561. 



Proptoptilum Carpenteri, 463. 



Pseudoraphidiea;, 433. 



Pseudorhombus, Eggs and Larvae of, 117, 128. 



Ptychocarpus, 350. 



R 



Radiation in Relation to the Disposition of Dew. 



By John Aitken, F.R.S.E., 33. 

 Rad stock Series of the Somerset and Bristol Coal 



Field, Fossil Flora of. By Robert Kidston, 



F.R.S.E., 335. 

 Ramage (G. A.), and Cunningham (J. T.), B.A., 



F.R.S.E. On the Polychaeta Sedentaria of the 



Firth of Forth, 635. 

 Rattray (John), M.A., B.Sc, F.R.S.E. On a 



Diatomaceous Deposit from North Tolsta, Lewis, 



419. 

 Rayleigh (Lord). On the Colours of Thin Plates, 



157. 

 Refraction. Tables for Facilitating the Computation 



of Differential Refraction in Position, Angle, 



and Distance. By the Hon. Loud M'Laren, 279. 

 Rhabdocarpus, 404. 

 Rhacophyllum, 387. 

 Rotation of a Sphere about each of the Principal 



Axes, 505. 



Rubidium, Chloroplatinate Method for the Deter- 

 mination of. By Professor W. Dittmar, 

 F.R.SS. L. and E., and John M'Arthur, 561. 



S 



Sabellaria, 652. 



Sabellidw, 668. 



Salmo, Eggs and Larva of, 111. 



levenensis, Larva of, 98. 



Sang (Edward), LL.D., F.R.S.E. On Cases of 

 Instability in Open Structures, 321. 



Schizostachys, 351. 



Scione maculata, 665. 



Scolecolepis, 639. 



Scoleples armiger, 642. 



Scomber, Ova of, 121. 



Scorpcena, Ova of, 118. 



Serolidce, Structure of the Eye in. By Frank E. 

 Beddard, M.A., F.R.S.E., 448, 451. 



Serpula, 672. 



Serranus cabrilla, Ova of, 118. 



Sigillaria, 396. 



Siluridce, Eggs of, 109. 



Siphonostoma typhle, Ova of, 129. 



Solenostomida}, Ova of, 129. 



Sorocladus antecedens, 143. 



Spiienophyllum, 344. 



Sphenopteris, 345. 



Spheres, The Partition of Energy between the Trans- 

 latory and Rotational Motions of a Set of Non- 

 Homogeneous Elastic Spheres. By Professor 

 W. Burnside, 501. The Averages of Rotation 

 of a Sphere about each of the Principal Axes 

 are equal, 505. The whole Average Energy 

 of Rotation of a Sphere is twice the Average 

 Energy of Translation, 505. 



One Set of Equal Spheres. By Professor Tait, 



67. 



Mean Free Path among Equal Spheres. By 



Professor Tait, 71. 



Spherical Functions. By P. Alexander, M.A., 

 313. 



Spinachia vulgaris, Ova of, 126. 



Spio, 640. 



Spionidm, 635, 642. 



Spiropteris, 387. 



Spirorbis, 674. 



Spongelia, Note on Peculiar Capsules found on the 

 Surface of. By J. Arthur Thomson, F.R.S.E., 

 241. 



Sporangia, 400. 



Stauroneis, 427. 



Stigmaria, 401. 



