CYTHERK. 163 



Genus 1 CYTHERE. 



CYTHEKE, Mi'dler, Latreille, Desmurest, M. Edwards, Sfc. $-c. 

 CYTHERINA, Lamarck, Sowerby, Munstcr, Roemer, 8fc. 8fc. 

 CYPRIDINA, Bosquet (not M. Edwards). 

 BAIRDIA, M'Coy, Jones* 



Character. One eye. Three pairs of feet; all ex- 

 ternal, none being inclosed within the shell. Abdomen 

 short. Inferior or pediform antennae furnished with one 

 tolerably long, curved and jointed filament. Superior 

 antennae simple, setiferous, and not provided with any 

 pencil of long filaments. 



Bibliographical History. Before Miiller's time the 

 animals of this genus were perfectly unknown, not the 

 slightest mention of their existence having been made by 

 any previous writer. As he is the first who has noticed 

 them, so he is the only author to whom we can refer for 

 any information respecting them, with the exception of 

 what I have added in my paper in the ' Mag. of Zool. 

 and Botany' for August 1837. Upon a slight inspection 

 the Cytheres might be mistaken for Cyprides ; but their 

 superior antennae,, being simple and free from the pencil 

 of long hairs with which these organs in the Cypris are 

 endowed, their possessing three pairs of feet, all of which 

 project out of the shell, and the want of the long tail or 

 abdomen, sufficiently distinguish the two genera. It is in 

 his ' Entomostraca' that Miiller first established the genus, 

 and the above marks of distinction between it and the 

 Cypris constitute almost all the knowledge that he imparts 

 to us concerning it. Meagre as it is in its details, it has 

 not been enlarged by any succeeding author. 



Gmelin, in the 'Syst. Nat.,' 1788, Eabricius, in his 

 'Ent. Syst.,' 1793, Manuel, in the 'Encyc. meth.,' 1792, 

 Latreille, in his 'Hist. Nat. Crust, et Ins./ 1802, either 



* The animal, in those recent species which have been referred by Mr. Jones 

 to the sub-genus BAIRDIA, M'Coy, and which I have had an opportunity of 

 examining, does not differ in the least from the animal of the Cythere proper. 



