19G NOTES AND MEMORANDA. 



valve, ratlier near the hinge. A few eggs were also attached to the 

 outer side of the same valve. 



Parent and progeny were placed in a small bell-jar under a siphon. 

 The circulation was occasionally stopped by accident, and a large 

 quantity of dirt accumulated from time to time at the bottom of the 

 jar around the eggs and parent. In spite of these drawbacks the latter 

 survived, and the eggs began to hatch out on the 1st December of the 

 same year. Most of them had hatched by the 10th December. The 

 newly-hatched young, about 22 mm. in length, more or less according 

 to the state of contraction, are reddish yellow in colour, and have, 

 essentially, the external features of the parent. 



The eggs, when trawled, were velvety in appearance, subsequently 

 becoming smooth and shiny, and finally, by the accumulation of dirt, 

 rather rough. No examination of the embryo was made at the time 

 of capture, but the appearance of the shell may probably indicate 

 that the eggs had not long been deposited. In any case it is evident 

 that the incubation of this particular clutch occupied at least 123 days, 

 and may reasonably be supposed to have been somewhat accelerated 

 by the warmer temperature of the Laboratory. After 136 days the 

 parent was still alive, though by no means vigorous. It was not 

 observed to make any attempt to leave the bell-jar, although there 

 was nothing to prevent it doing so, nor was it noticed to occupy any 

 constant position in relation to its eggs. No food whatever was 

 supplied. 



For what purpose the skate-leech remains with its eggs during 

 incubation appears uncertain. One may presume that their protection 

 is the chief object: whether from active enemies or from the mere 

 accumulation of sand, &c., is doubtful. The Uocculent diatomaceous 

 dirt which accumulated in the vessel in wliich our specimen was 

 confined was too light to be removed, and appears to have been 

 quite innocuous. No experiments were made with sand or other 

 matters. 



Hatching is accomplished by the perforation of the membrane of 

 one of the fenestrie. The chitinous part of the shell is not ruptured 

 in any way. 



Larval Lobsters at the Surface. Although young lobsters must 

 be plentiful, they are but rarely encountered in our tow-nets. During 

 1897 we have only taken them on three occasions. On the 10th July, 

 while the Busy Bcc was trawling in the outer part of Falmouth Bay, 

 Mr. Vallentin caught one in a hand-net. The sea was absolutely calm, 

 and we saw a great many " mackerel-midges " {pelagic MotcUcc) and 

 caught a quantity of brachyurous zoiiie, apparently Portunus, These 



