LIMNORIA. 
227 
Gen. 111. TANAIS, Milne- Edwards. 
Similar in many respects to the last. Antennae very short, 
without many-jointed thread at the end. Second pair of 
legs similar to the following pair. The three first rings of 
abdomen more developed than the following. 
Tanais Dulongii, Audouin, sp* — Upper antennae much 
thicker, but scarcely longer than the lower. Five last pairs 
of legs nearly of the same length. Abdomen without hairs 
on the sides. Two lines long. 
Irish coast, Giant's Causeway (W. Thompson) . 
Gen. 112. LIMNORIA, Leach. 
Body capable of being contracted nearly into a ball. 
Eyes distinct, granular. Tail of many segments, scarcely 
narrower than the body, the last somewhat rounded. An- 
tennae in pairs, one placed over the other. 
Limnoria lignorum, Rathke, sp. Boring Limnoria . 
(Plate XII. fig. 5.) — Body ash-coloured; eyes dark-brown. 
Woodwork in the sea. Common. 
This very destructive little boring creature was first 
* Westwood proposes to separate this species under the name of Aniso - 
ckeirus. Ann. Sc. Nat. xxvii. p. 330. 
