242 CRUSTACEANS. 



But a zealous and skilful naturalist, Dr Coldstream, having subse- 

 quently published an account of his own observations on the subject, I 

 shall here confine myself to a few personal notices. 



Though new to most naturalists, from its attacks on the Chain Pier 

 at Newhaven, I was informed in the year 1827, that the flood-gates of 

 the Wet Docks at Leith were infested by the Limnoria eleven years pre- 

 viously ; probably, because a copious influx of fresh-water from the 

 interior of the country was discharged within them. Its ravages had 

 been also witnessed by the late Mr Robert Stevenson, an eminent engineer, 

 on the wooden structures employed by him in erecting the Bell Rock 

 Lighthouse, seventy or eighty miles from Trinity Chain Pier. 



As the nature of the animal in question savours much of that of the 

 two preceding, perhaps it might have been conveniently incorporated 

 with them, under suitable distinctions, in the Oniscoid genus, instead of 

 instituting a new one for its reception, where, I believe, it yet stands 

 single. This was done, however, by the late Dr Leach, a naturalist pro- 

 foundly versed in the history of the Crustaceans. 



In appearance and in motion, this creature resembles a diminutive 

 specimen of the Aphrodita squamata. 



The body is linear and flattened, the back slightly convex. It is 

 composed of seven segments, besides the head, bearing four antennte and 

 two eyes ; and the last segment with two styles like the Asellus. But 

 these segments are so indented and subdivided as to appear fourteen in 

 all. Fourteen limbs are arranged below in seven pair. The form of the 

 head is rounded, with much similarity to that of a cat, having a large 

 black eye on each side, composed of about seven specks, one being in the 

 centre. The antennae are nearly of equal dimensions, each pair appa- 

 rently consisting of four and five articulations respectively, thickly beset 

 with hairs, and terminating in bristly pencils. 



The segments of the body are deeply divided, the whole being 

 covered with hairs. Four follicles constitute the under part of the pos- 

 terior extremity. 



Much diversity of size prevails among these minute animals, which, 

 full grown, seem to be about a line and a half in length, and half a line 

 in breadth. 



