374 Proceedings of the Royal Physical Society. 



brane enclosing the new chelate limbs remained unburst (?), and was 

 cast off with tlie exo-skeleton during ecdysis, remaining attached to the 

 basal joint in each case. After ecdysis the new limbs increased rapidly 

 in size, and had assumed considerable proportions before the new shell 

 became hardened, a process which usually occupies several days. 

 Owing to liability to irregularity in measurements of the total length 

 of chelate limbs, I have taken the relative size of the terminal (pincer) 

 joint as a safer guide in comparisons. The length of the pincer joint 

 in the limbs thrown off 5, iii. 83 was, for that of the right limb, 3^ 

 in. ; and of the left, 3 j% in. When the new skeleton became thoroughly 

 hardened, the corresponding joints of the new limbs measured respec- 

 tively, 2| and 2 4 in, 



Tlie neAv antenna on this date had attained a length of 5 or 6 in., 

 but unfortunately it received an injury, and the terminal portion broke 

 away, so that I am unable to give precise measurements. 



This specimen died 1, i. 84, before any further ecdysis had taken place. 



Lobster B. 



Had lost during the winter (no precise date kept) the right chela, the fifth 

 leg on the right side, and the fourth on the left side. 



13, iv. 83. — Rudiment of pincer claw about 1 in. long, and extends a little 

 beyond the middle of the third joint (ischiopodite) of the third pair of 

 limbs. Rudiments of the lost ambulatory limbs reach to about the 

 middle of the fourth joint (meropodite) of the preceding leg. The 

 new limbs are imllid white, tinted with flesh colour, and have the full 

 complement of joints. These are, however, quite rigid. 



11, V. 83. — Process of chela 1| in. long; other legs 1 in. long. The new 

 limbs have acquired the same tints, and are quite as dark as the 

 uninjured ones, but are distinguished by being very shining on the 

 surface — due, no doubt, to the enveloping membrane. 



19, V. 83. — Ecdysis has taken place during the past night. The limbs have 

 attained their proper proportions, and the lobster moved about actively 

 when first observed, exhibiting none of the abject fear frequently 

 shown by other specimens immediately after ecdysis. It had partially 

 buried its cast shell under the gravel. During the previous fortnight 

 this specimen has shown great irritability and pugnacity, and when 

 offered food seized it savagely ; but instead of eating, proceeded im- 

 mediately to bury it. 

 Yesterday afternoon noticed this specimen rubbing its body against the 

 sand, and bending the abdomen upwards, so as to stretch the ventral 

 membrane uniting the cephalothorax with the abdomen. For some 

 reason, which was not ascertained, the lost antenna (left) was not 

 reproduced at this ecdysis. The relative size of the chelse before and 

 after ecdysis will be seen on reference to the general table. One point 

 is worthy of note in regard to the ambulatory limbs. After this 

 ecdysis the new ambulatory limbs assumed all the proportions of their 



