290 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



XXX. 

 JOTTINGS FROM MY NOTE-BOOK, 



BY DAVID ROBERTSON, F.L.S., F.G.S. 



Pagurus Prideauxii, Leach, 



[Read 9th June, 1885.] 



This crab is well-known for its constant association 

 ^\'ith the Hydrozoon Adarnsia palliata. 



Many years ago, while observing some fishermen 

 lifting their nets on Lochfyne, I noticed that in 

 several places in the nets there were two of these 

 crabs together, each couple consisting of a larger 

 And a smaller individual. It occurred to me after- 

 wards that they might be male and female, but I 

 neglected the opportunity of examining them at 

 the time. When dredging I often afterwards met 

 with males and females ; but as the dredge had 

 raked over a considerable part of the sea-bottom, I 

 could not say that they had been taken together. 



Some time afterwards, during a very low tide, a 

 favourable opportunity occurred of seeing at different 

 places three pairs — male and female — together. I 

 ^m therefore strongly led to suspect that they pair, 

 and that they probably prove true to each other. 

 If so, we may presume that the weaker shares the 

 protection of the powerful pincers of the stronger 

 sex. 



Amphidotus cordatus, Penn, 



[Read 26th January, 1886.] 



The source of the mucus thrown out by this 

 animal under irritation has long been a puzzle; 

 and, so far as I know, it still remains so. In the 



