Dr. Lracn’s Arrangement of the Crustacea, $c. — 371 
Antenne inferne per paria insertæ, unà super alteram posit. ` 
Oculi e granulis (*octo aut septem) efformati. 
Spec. 1. Limnoria terebrans. 
L. corpore cinereo, oculis subpiceo-atris. 
Limnoria terebrans. Leach, Edin. Encycl. vii. 433. 
Long. Corp. 1 lin. et 14 aut 2 lin. 
This new and highly interesting species I received through the 
politeness of my attentive and worthy friend R. Stephenson, Esq. 
It occurs in the greatest abundance at the Bell Rock, in the old 
wood-work used whilst the lighthouse was building, which it per- 
forates in a most alarming manner, entering to the depth of two 
inches or more, boring in every direction. They seldom or never 
deviate from a straight line in their perforations, unless inter- 
rupted in their progress by a knot in the wood, when they pass 
round it. The female is one-third larger than the male, and may be 
readily distinguished by its pouch, which is easily seen, and in 
which the eggs and young ones after their exclusion are carried. 
The young ones in those I examined were generally seven in num- 
ber, in some few nine, and in one instance only five. When alive it 
can contract nearly into a ball. I was at first induced to place it 
in the genus Cymothoa, but a more careful observation clearly 
proved it not to be referable to that genus. 
Gen. 29. Cxwornoa, Fabr., Dald., Latr. 
Caput angustum, parvum.  Segmentum secundum antice emargi- 
natum ad caput recipiendum, angulis anticis porrectis cum 
capite lineam rectam delinientibus. Cauda segmentis plurimis 
corpore angustioribus, ultimo majori transverse subquadrato, 
basi utrinque stylis duobus pediculo impositis. Oculi obscuri. 
* | mention the number with some doubt ; seven granules are arranged in a circle, and in 
a certain light there seems to be another in the centre, 
VOL, XI. | ; 3c Spec. 1. 
