302 
HISTORY OF BRITISH CRUSTACEA. 
tip into two sharp points, and ending at the base on each 
side in a sharp, hooked spine. Thorax in six, abdomen in 
four, segments. Antennules not two-branched. Anterior 
antenna of male geniculated, swollen. Toot-jaws strongly 
developed. Eye in the male pedunculated. Mr. Lubbock 
has observed five eyes in this genus, four upper, one lower.^ 
The species swims with a lively and constant motion, and 
jerks out of the way when pursued. 
Anomalocera Patersonii. (Plate XYIII. fig. 1.) — It 
is about three lines long, and when alive is very brilliant. 
Mr. Goodsir describes it as having a luminous appearance, 
apparently caused by the splendid metallic colours with 
which it is adorned, sapphirine and emerald prevailing. 
These colours disappear rapidly after death. 
Hab. Irish and Scotch coasts. 
Tam. III. CETO CHILIDJE. 
Head distinguishable from body, but firmly articulated 
with the first ring of thorax. Three pairs of strongly deve- 
loped foot-jaws. Five pairs of legs. Two eyes. Eight an- 
tennae in male furnished with swollen hinge-joint. 
* Ann. and Mag. Nat. Hist. 1853, pp. 164, 165. 
