1889.] ON SOME FRESHWATER OSTRACODA AND COPEPODA. 49 



of the valves (see fig. 1, 11) are not very large, that of the an- 

 terior extremity being somewhat broader, especially in the fe- 

 male. The shell-structure, as appearing by transmitted light (fig. 

 2), shows numerous irregular, angulated facets of an opaque ap- 

 pearance, lying close together. 



As to colour, the shell of adult females is rather opaque, of 

 a dull white or greyish hue, with a slight greenish shade in 

 the dorsal part. That of the adult male is far more pellucid 

 and more or less mottled with small purplish brown dots. 



The eye (see PI. VI, figs 1 & 11) is not very large and has 

 its place at a considerable distance below the upper margin of 

 the shell. Its structure would also seem to be somewhat more 

 simple than in the forms described above. 



The upper antennse (fig. 3) are rather powerful, with the 

 basal part very thick and muscular. The joints of the terminal 

 part successively diminish in thickness but less so in length 

 than in most other Cyprididae. The last joiut is rather narrow, 

 sublinear and bears at the tip 3 not very long, spiniform bristles, 

 somewhat pointing upwards. The preceding joints are each 

 provided with 2 natatory setae on either side, those of the an- 

 terior edge being excessively long and slender and forming 

 together a dense fascicle, almost equalling the whole antenna 

 in length. 



The lower antennas (fig. 4) are likewise rather powerful, 

 and of the usual structure. The apical claws are not very 

 elongate and quite smooth. The natatory setae, on the other 

 hand, are very long and slender, reaching considerably beyond 

 the tips of the claws. 



The mandibles (fig. 5) have a rather strong and somewhat 

 curved corpus, the lower part of which is highly chitinised 

 and exhibits the usual armature of masticatory teeth. The palp 

 18 very thick, especially the basal joint, which bears a well 

 developed branchial appendage. 



The 1st pair of maxillae (fig. 6) somewhat resemble those 

 organs in the genus Herpetocypris, the palp being rather large, 

 with the 1st joint considerably dilated towards the end and an- 



Vid.-SeUk. Forh. 1889. No. 8. * 



