328 ASELLIDA. 
terior angles. The last segment is almost triangular ; the 
apex being directed posteriorly, two small styles arise 
from each side of the apex.” 
[We have copied Mr. Goodsir’s figure of the tail at z, 
which shows that there is only one pair of caudal styles, 
and not two pairs, as his description would lead us to 
infer.] ‘* All the external margins of both of these 
segments are thickly fringed with minute hairs and 
spines. The branchiz are almost semicircular, and each 
of them is armed on its internal edge with a small 
appendage. The external plate of the branchie is 
extremely narrow, and is not composed of two equi- 
lateral pieces, as in the other Asellide, but consists of 
one piece only, with an immovable suture in its mesial 
line. It is attached to the body by its base only.” 
This species was found by the late Mr. H. Goodsir in 
the Frith of Forth. It is quick and active in its move- 
ments, running among the branches of coralline with 
great rapidity. Mr. Goodsir never observed it swim- 
ming, its legs being, indeed, unfitted for that kind of » 
locomotion; when pursued along the bottom, it runs 
quickly, but often stops suddenly, turns round, and 
assails its annoyer. We have received it from Mr. 
Robertson, who took it at Kames Bay, and from the 
Rev. A. M. Norman, who found it at Cullercoats and 
Seaham. 
