of the Fishery Board for Scotland. 



155 



One spermatheca was empty ; the other had a large quantity of sperms 

 in it. The swimmerets had still some empty egg-capsules attached. In 

 the crab which was killed the ovary was the colour of the external eggs. 

 It was friable. The spermatheca contained a good quantity of sperms. 

 The endopodites of the swimmerets were clean. 



In October 1903 two of the crabs spawned. One which was killed 

 had an ovary that appeared to be ripe ; the eggs measured -37 and *4mm. 

 in diameter. There was a copious supply of sperms in the spermatheca. 



On January 13th 1904 another crab was found to have spawned. On 

 February 14th 1904 two of the non-berried crabs were dead. In one, 

 measuring 6 inches across, the ovary was small and white, but mottled to a 

 considerable extent here and there with red eggs. This crab had evi- 

 dently spawned this season, although the eggs had not remained attached 

 to the swimmerets. There was a small quantity of sperms in each 

 spermatheca. The second crab measured 7^ inches across. The ovary 

 was dropsical. There was a large quantity of sperms in both spermatheca. 

 There were lots of empty egg-capsules on the endopodites of the 

 swimmerets. 



On October 31st 1904 there were five crabs remaining of the 1902 

 batch. One was berried. On November 19th 1904 two of the crabs were 

 berried. In December 1904 and January 1905, three crabs were found 

 dead. On January 12th 1905 two crabs remained; one of these was 

 berried. Both crabs were found dead on May 6th 1905. During the 

 whole period not one of the crabs cast. 



Casting. — The Absorption Areas on the Chela. 



In a previous paper I described the absorption which takes place on 

 the three proximal joints of the chela at the time when the crab casts, 

 whereby the withdrawal of the chela from the shell is facilitated. I was 

 not aware at that time that a detailed description accompanied by drawings 

 had been published by J. Couch.* 



* J. Couch. " A particular description of some circumstances hitherto little known, 

 connected with the process of Exuviation in the Common Edible Crab." Twenty-sixth 

 Annual Report of the Royal Cornwall Polytechnic Society, 1858. 



