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. Foot-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 XYIIL 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. 



Fam. III. CETOCHILIDJE. 



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. Right an- 

 tennae in male furnished with swollen hinge-joint. 

 * Ann. and Mag. Nat. Hist. 1853, pp. 164, 165. 



