RECENT BRITISH OSTRACODA. 453 



G. O. Sars gives the following curious description of the male copulative organs. " By 

 a wonderful freak of nature these have the appearance, when seen from the side, of the 

 head of a bald old man. The basal portion represents the skull, the terminal portion the 

 long beard, and the intervening parts the profile with forehead, nose, and mouth. To 

 make the resemblance more complete, some chitinous bands produce, in the proper 

 position, an eye with pupil and highly elevated eyebrows. These organs present in 

 various orders of Crustacea so many variations that, by the help of a little fancy, it is 

 easy to make each species represent some particular object. But here the resemblance is 

 so exact that it must needs strike every observer." 



Genus 11. Psetjdoctthere, G. O. Sars. 

 Shell thin and pellucid, having no distinct structure, rounded in front, produced 

 behind. Hinge-joint simple. Upper antennse bearing long setse, 7-jointed; second joint 

 thick and armed with a single seta on the middle of the anterior margin ; last joint very 

 long and narrow, linear, terminating in very long seti3e ; lower antennse very slender, 

 5-jointed ; flagellum long and slender. Mandibles small, with slender, curved, unguiform 

 teeth ; palp narrow, 4-jointed ; branchial appendage bearing long setae. Terminal lobes 

 of the first pair of jaws narrow ; branchial plate large, elongate-ovate, armed towards the 

 base with three curved and deflexed simple setee. Peet very long and slender. Abdo- 

 men ending in a long, slender process ; postabdominal lobes almost as in the preceding 

 genus. No eye. 



Though very nearly related to the foregoing, the characters given by G. O. Sars 

 appear to be amply sufficient to constitute Fseiidocythere a distinct genus. The form of 

 the carapace is, indeed, so peculiar as at once to suggest its distinctness ; and there are 

 also important difi^erences in the structure of the antennae and mandibles. The only 

 member of the genus is 



PsEUDOCYTHERE CAUDATA, G. O. Sars. (Plate XXXIV. figs. 49-52, and Plate XLI. 

 fig. 6.) 



Pseudocythere caudata, G. O. Sars, loc. cit. p. 88. 



Carapace of the male, as seen from the side, quadrilateral, highest in front ; greatest 

 height equal to more than half the length. Anterior margin broad and well rounded ; 

 posterior obliquely truncate, produced above into an obtusely conical beak. Superior 

 margin sloping in a somewhat sinuous line from before Ijackwards ; inferior slightly 

 sinuated in front, terminating behind in one or two small sharp teeth. The anterior 

 and ventral margins form a thin flattened lamina, which is marked with radiating trans- 

 verse lines, and is most strongly developed behind. Shell of the female rather more 

 tumid. Outline, as seen from above, compressed, oval, tapering to the extremities, which 

 are slightly mucronate ; greatest width in the middle and equal to one-third of the length. 

 Shell smooth, thin, and fragile, bearing scattered short hairs ; pellucid, the brown body 

 of the animal showing through the shell. Lucid spots four, linear, parallel, situated 

 obliquely a little in front of the middle. " Last joint of the upper antennse much longer 



