144 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



I have kept the female for months at a time, and 

 found that it burrows, posterior end downwards, 

 remaining for weeks with the points of the antennae 

 just above the sand, which may account for the algae 

 found only on that part of the animal. 



The abdominal relates of the female of this species 

 are smaller and less fitted to cover the ova than is 

 generally the case among the Bracliyura or short- 

 tailed family, but the burrowing habits compensate 

 for the small abdominal plates in protecting the 

 uncovered ova. 



Mr. Bell mentions that he took ten in one day in 

 the shrimp-trawl, all females ; and we may reason- 

 ably infer, from their having been taken in the 

 trawl, that they were captured on the surface. As 

 the habits of the young Crustacea, however, often 

 differ greatly from those of the adults, it may have 

 been that these females were all young, or not in 

 ova, and therefore not in a condition requiring 

 their concealment under the sand. 



In reference to the habits of the male, it may be 

 as^ed whether, like the female, it too may habitually 

 burrow in the sand ; but the growth of the algae on 

 the body and legs proves that sometimes at least it 

 must remain on the surface for a considerable time. 



This species is by no means common at C umbrae ; 

 but it will be of interest when a living male should 

 occur, to ascertain whether he burrows and spends 

 as much of his time under the sand as the female 

 seems to do. It will also be interesting to know 

 whether the barren female continues to burrow, 

 keeping herself free of algae. 



Mytilus edulis, Lin. 



[Read 30th November, 1886.] 



Last summer I had a walk along the shores of the 

 Clyde at Cardross. The water there, at that season, 

 is decidedly brackish ; but during winter the fresh 

 water must greatly prevail. Opposite the Railway 



