332 BRITISH ENTOMOSTRACA. 



Males in general differ very much in appearance from 

 the females, being greatly smaller and unattached. 



Family LERNEOPODAD.E. 

 LERNEOPODIENS (pars), M. Edwards, Hist. Nat. Crust., iii. 



Character. Arm- shaped appendages long, wide apart 

 from each other at their base, and united only at the tip. 



Genus LERNEOPODA.* 



LERNEOPODA, Blainville, Journ. Pliys., xcv, 442, 1822. 



Kroyer, Tidsskrift, i, 207. 



M. Edtcards, Hist. Nat. Crust., iii, 514. 



W. Thompson, Ann. Mag. Nat. Hist., xx, 248. 



Rathke, Nov. Act., xix. 

 LERNJJA, Gisler, Linnccas, Grant, Retzius, $-c. 



Character. Female. Body generally elongated, oval. 

 Head short and thick. Two pairs of foot-jaws, well- 

 developed, and placed near each other. External ovaries 

 of moderate length and cylindrical. 



Male. Body divided into two nearly equal portions of 

 an ovoid shape ; one representing the head, the other the 

 thorax. Much smaller than the female. 



The genus Lerneopoda was established by Blainville, 

 in the 'Journal de Physique/ in 1822; and was after- 

 wards adopted by Nordmann in 1832, Burmeister in 

 1835, and Kroyer, in his 'Tidsskrift/ in 1837 ; but the 

 first notice taken of any species appertaining to the genus 

 was by Gisler in 1751, who, in the twelfth volume of the 

 ' Acta Suecica,' describes and figures a species of Lernea 

 found by him on the salmon, and which he called "Pedi- 

 culus salmoms or Lax-lusen."\ 



Linnseus, in his 'Fauna Suecica,' 1761, describes this 

 species as the Lerncea salmonea, and repeats it in his 



f Aipmiioc, belonging to Lernea : and TTOVC, foot, 

 t " Salmon louse." 



