10 



Part III. — Twenty-second Annual Report 



discovered that they are skewered on to the long delicate hairs with 

 which the inner branches of the swimmerets are provided, and are 

 not, as has generally been believed, fixed to them by a mucilaginous 

 secretion. The eggs themselves are never found cemented together 

 although crowded in close contact. The mode in which the eggs 

 are skewered on to the stiff hairs is as follows. When the eggs 

 are extruded they imbibe sea water and become swollen, so that 

 the egg-mass is separated from the shell, and this space soon 

 attains large dimensions. The eggs are retained in a semi-fluid 

 mass in the " apron " of the crab, and by the continuous stabbing 

 movement of the stiff hairs on the swimmerets the eggs are pierced 

 and skewered as described. Dr. Williamson also treats of the rate 

 of growth, the migrations, and the distribution of the crab, and in 

 connection with the former subject had the use of the data 

 furnished by Mr. Waddington, Bournemouth, of the various 

 successive casts of certain edible crabs which had been kept in 

 confinement for periods up to two years, and these are represented 

 in a series of figures, and are of much interest. 



Further descriptions are given of the results of labelling crabs 

 which were afterwards liberated, in order to throw light on their 

 migrations. In contrast to some of the previous results, it may be 

 said that one of the labelled crabs, an adult male, was obtained 

 three years after its liberation very near the spot where it was set 

 free. 



The Young of the Witch Sole. 



During the trawling investigations in the Moray Firth a very 

 complete series of the young of the Witch Sole was obtained, one 

 of the flat-fishes now brought to market in considerable numbers 

 by the trawlers working in deep water, and in the knowledge of 

 whose life-history there were considerable gaps. Dr. Williamson 

 describes these in a paper in the present Keport. Some dubiety 

 has existed as to the identity of the post-larval stages of this form, 

 which differ from the corresponding stages of most flat-fishes by 

 their great length and slenderness, as well as by other characters, 

 so that the first one described was supposed to be a young halibut. 

 The present series, by filling up the blanks between the previously- 

 recorded stages, completes the chain connecting the egg with the 

 parent fish. The paper is illustrated with a number of figures. 



The Marine Crustacea. 



In this Keport will be found a paper, illustrated by three plates 

 of figures, by Dr. Thomas Scott, descriptive of a number of rare 

 Crustacea, obtained for the most part during the trawling investi- 

 gations. The forms described are all small, and include two groups 

 of the Copepoda that are somewhat abnormal both in their 

 structure and habits. Among the nine species belonging to the 

 first of these groups — the Monstrillidse — three are new to science 

 and are now described for the first time, and of the seven species 

 which belong to the second of the groups — the Choniostomatidse — 

 five are new to science and are here described for the first time, 



