of ike Fishery Board for Scotland. 143 

 Table XJII. 



Analysis of Da ily Statistics — September, October, November, December, 

 1899, and January, 1900. 



1899-1900. 



Number 



of 

 Times 

 at 

 Sea. 



Gauge Crabs— inches and over. 



Under-Gauge 

 Crabs. 



Hard 

 Crabs. 



Soft 

 Crabs. 



Total 

 Number 



Hard 

 and Soft. 



Percentage 

 of 

 Hard. 



Percentage 

 of 

 Soft. 



Average 

 Number of 

 Soft Crabs 

 each day. 



Hard. 



Soft. 



September, 1899, 



12 



2,147 



8,674 



10,821 



20 



80 



723 



4 



30 



October, ,, 



20 



4,564 



5,595 



10,159 



45 



55 



280 



3,657 



3,144 



November, ,, 



13 



3,826 



2,752 



6,578 



58 



42 



212 



762 



1,920 



December, ,, 



15 



6,144 



1,701 



7,845 



78 



22 



113 



1,383 



241 



January, 1900. 



10 



3,531 



66 



3,597 



98 



2 



8-5 



99 



49 



DESCRIPTION OF PLATES. 

 PLATE I. 



Fig. 1. Vagina and Spermatheca of a Soft Crab 5| inches across, o., ovary : pi., 

 plug : ant. , anterior surface : pst. , posterior surface. 



Fig. 2. Larva of Carcinus mcenas, second stage. 24 hours after hatching. 

 August 2nd, 1899. 



Fig. 3. Vaginal plug, a., the half next the median line of the thorax : b., the 

 half next the outer edge of the thorax. 



Fig. 4. Larva of Cancer pagurus, second stage. 15 minutes after hatching. 



July 21st, 1899. sp., lateral spine. The outer branches of the 

 maxillipedes are shown on the right side only ; and the inner branches 

 of the same are alone shown on the left side. 



Fig. 5. Spermatheca and Vagina of a Soft Crab inches across, ss., the secret- 

 ing inner surface of the Spermatheca : o., ovary : v., vagina. 



Fig. 6. Spermatheca and Vagina of a Soft Crab, showing plug in situ: sp., wall 

 of spermatheca : v. , wall of vagina : pi. , plug. 



Fig. 7. Dissection of the Chela of a Crab near the fracture-plane, showing the 

 two septa, c, which remains attached to the cast-off limb : d., which 

 remains on the basi-podite. a., the basi-ischiopodite joint: b., 

 meropodite. 



Fig. 8. Portion of Vaginal Plug found on the abdomen of a male crab : pi. , plug : 

 ap. , anterior element of penis : pp. , posterior element of penis. 



Fig. 9. Spermatheca of Hard Crab ; sm. , mass of sperms : si. , secretion of sperma- 

 theca, solidified, ood., opening of oviduct. 



Fig. 10. The Carapace of a Male Crab, a., and of a Female Crab, b., natural size, 

 6^ inches across. 



Fig. 11. Spermatozoon of Cancer pagurus : a., seen from above, b., seen from the 

 side. 



PLATE II. 



Curves of the measurements of Beach Crabs. The divisions on the abscissa denote 

 centimetres ; on the ordinate are marked off the number of individuals. 



PLATE III. 



Curves of the measurements of Beach and Creel Crabs. The standard of measure- 

 ment is an inch. 



PLATE IV. 



Chart of a portion of the coast near Dunbar, showing the places where the Marked 

 Crabs were recovered (vide p. 121), 



