Vol. 3] Judmj. — Ostracoda of the San Diego Region. 139 



branch usually developed as a grasping organ in the male, some- 

 times rudimentary in both sexes. Mandibular palp usually four- 

 jointed and very strong, last joint bearing claws. The seventh 

 pair of appendages originates high up on the sides of the body; 

 these limbs are long, many jointed, and worm-like. Furca always 

 strong and armed with several spines. 



Genus Philomedes Lilljeborg, 1853. 



Mature female. — Shell always with a distinct rostral sinus 

 overhung by a broad, blunt rostral process ; postero-ventral angle 

 often produced into a more or less distinct projection. Eyes 

 small or wanting. Frontal organ long and slender. Antennule 

 six-jointed, with rather long, sparsely plumose setae ; no sensory 

 seta. Antenna with a small secondary branch. Basal joint of 

 mandible with a masticating process which is cleft at the apex; 

 first joint of palp with some masticating spines at the base. First 

 maxilla rather large and strong; second maxilla with two rather 

 large teeth at the anterior corner, the inner tooth being smaller 

 than the outer and bifid. First pair of legs more or less distinctly 

 jointed ; outer extremity separated into lobes. 



Mature male. — Shell more elongated. The fifth (fourth) joint 

 of the antennule with a sensory seta which bears a number of 

 long sensory filaments ; last joint with two very long setae which 

 are usually reflexed upon the limb. Secondary branch of antenna 

 three-jointed, prehensile, the last joint reflexed upon the second. 

 Mandible without masticating processes. First maxilla only in- 

 distinctly joined, small, weak, armed with delicate setae. Second 

 maxilla without teeth. Eyes well developed. 



Philomedes longiseta no v. sp. 



PI. IS, figs. 13-15. 



The shell of the male, in side view, is oval in outline, all the 

 corners being rather evenly and regularly rounded; dorsal mar- 

 gin broadly and regularly arched, ventral moderately arched; 

 posterior margin curving off gradually into both dorsal and ven- 

 tral margins, forming a bolder regular arch. The rostral process 



