4 



CONTENTS. 



PAGE. 



Size of Crab at Maturity : — 



The Mature Female Crab .... 79 



Fertilisation ...... 82 



Annual Spawning . . . . .85 



Times of Spawning and Hatching . . .88 



Number of Eggs of Berried Crab . . .89 



The Mature Male Crab . . . .97 



External Sexual Characters ..... 98 



Proportional Numbers of tne Sexes ■ . . .99 



Exuviation, Casting ...... 104 



The Occurrence of Soft Crabs .... 105 



Frequency of Casting . . . . .109 



Regeneration of Lost Limbs : the Repair of Injuries . . Ill 



Rate of Growth and Distribution . . . .113 



The Migrations of Crabs . . . . .119 



The Regulation of the Crab Fishery . . . .134 



Description of the Plates ..... 143 



III. Notes on some Crustacean Parasites of Fishes. By Thomas 



Scott, F.L.S., Mem. Zool. Soc. de. France. (Plates 



v.-vin.) 



Introductory Note ...... 144 



Copepod-Parasites of Fishes ..... 145 



„ „ „ — Ergasilidre . . . 146 



„ „ „ — Caligidre .... 147 



„ „ „ — Dichelesticb^e . . . 159 



„ „ „ — Lemseidse . . . 160 



„ „ „ — Chondracanthidre . . 163 



„ „ — Lernseopodidze . . .169 



Branchiura . . . . . . .179 



Isopoda parasita . . . . . .180 



Amphipoda parasita . . . . . ..180 



List of Fishes on which Copepod-Parasites have been found . 181 

 Concluding Remarks . . . . . .182 



Description of the Plates ..... 183 



IV. Contributions towards the Natural History of the Plaice (P. 



platessa, L.). By H. M. Kyle, M.A., B.Sc, Exhibition 

 Science Scholar, St. Andrews. (Plates IX. -X.) 

 Introduction . . . . . . .189 



Average-Size at First Maturity . . . . .190 



Variability and the Method of Treating Variations . . 201 



The Various Forms of Variability .... 207 



I. Sex-Variability . . . . .207 



II. Growth- Variability . . . . .212 



III. Race-Variability . . . . .220 



Conclusion . . . . . . 237 



V. Report of an Enquiry on the Action of the Herring Seine-Net. 



By T/Wemyss Fulton, M.D., F.R.S.E., Scientific 

 Superintendent ...... 242 



VI. The Fishes of the Firth of Clyde. By Thomas Scott, F.L.S., 



Member Soc. Zool. de France .... 272 



VII. On the Mackerel of the East and West Coasts of Scotland. By 



H. Chas. Williamson, M.A., B.Sc, . . .294 



