382 IDOTEIDA. 
with the lateral angles scarcely prominent, and the mid- 
dle tooth only very slightly developed, have been con- 
sidered as distinct species by M. Polydore Roux, who 
has carefully figured a number of varieties; those 
marked with pale spots being his J. variegata, and the 
unicolorous ones his J. Bastert. We agree with Pro- 
fessor Milne Edwards in considering them as mere 
varieties. 
Specimens of this species from the Cornwall and 
Devonshire coasts, as well as from Scotland, are con- 
tained in the collection of the British Museum. The 
largest specimens we have seen (measuring one inch and 
five lines and an inch and a quarter long) were forwarded 
to us, the former by Mr. Byerley from the Cheshire 
coast, the latter was taken off the Dudman, on the coast 
of Cornwall. There are also numerous specimens from 
different Irish localities in the Belfast Museum, collected 
by the late Mr. W. Thompson, Professor Allman, 
Mr. Hyndman, Dr. Drummond, and Mr. Patterson; Co. 
Cork, Mr. Humphreys, ‘“ Contributions to Fauna of Co. 
Cork.” 
Sir J. G. Dalyell has described and figured some varie- 
ties of this species in his ‘* Powers of Creation,” vol. i. 
p- 228, pl. Ixiil. fig. 5—9 and 10, under the names of 
** Oniscus balthicus (Idotea marina),” and Entomon. “ Full- 
grown specimens measure, from the tips of the antennz 
to the posterior extremity, twenty-one lines in length. 
Their colour is dingy or brownish-yellow, with three 
or four white specks down the centre of the back; or it 
is altogether of variegated hues, and some are mottled. 
The variegated specimens are beautiful animals, espe- 
cially when first appearing in their new shells.” He 
observes that “this creature feeds voraciously, seizing 
and carrying off prey in its fore limbs. It also devours 
