324 HISTORY OF BRITISH CRUSTACEA. 



Gen. 181. NICOTHOE, Edw. 8f Audouin. 



Two eyes ; antennae slender, many-jointed ; foot-jaws very 

 small. Thorax of female enlarged on the side into two large 

 wing-shaped lobes ; in the male these appendages are want- 

 ing. There are four pairs of feet, which are two-branched 

 and jointed. The body is jointed. 



The species of this curious genus is found attached, often 

 in considerable numbers, to the gills of the common Lobster, 

 and remains firmly fixed among the filaments of these organs. 



The male, according to Professor Yan Benedeu,"* is much 

 smaller than the female, and leads a free life, as does the 

 young female at first : as soon as the latter fixes itself to the 

 branchise, lateral prolongations appear, to the height of the 

 fourth thoracic ring. In the adult state these appendages 

 seem to form the whole animal. 



Nicothoe astaci, Aud. & Edw. Lobster Louse. (Plate 

 XX. fig. 1.) — Of a rosy hue, about a line long. Dr. Baird 

 has found it on the gills of the Lobster in the London 

 market in March and April, and Mr. Cocks in a Lobster 

 taken at Ealmouth, in September. 



* Memoire sur le Dt'veloppement, etc., des Xicothoes, in vol. xxiv. of 

 the Memoires de l'Academie Royale de Belgique. 



