Vol. 3] Juday. — Ostracoda of the San Diego Region. 147 



Second and third maxillae very similar to those of Philomedes. 

 Vermiform limb with one lateral and four terminal setae. The 

 fnrea is short and snb-triangiilar ; the marginal appendages con- 

 sist of stout, spinous, pectinated claws and weak, seta-like struc- 

 tures ; the upper two are small claws, the next three are setae, fol- 

 lowing these is a stout claw, then two more setae, another stout 

 claw, and lastly, the large terminal claw. 



Length 1.2; height 0.75 mm. 



Female unknown. 



Two males, catch 571, Ballast Pt., San Diego Bay, July 26, 

 1901 ; two males, catch 589, San Pedro, August 1, 1902. 



Family RUTIDERMATIDAE Brady & Norman, 1896. 



Antennule of female without sensory organ ; antenna without 

 secondary branch. Mandibular palp with last joint very large, 

 terminating in a strongly developed chela. 



Genus Rutiderma Brady & Norman, 1896. 



Shell oval, truncate behind; antennal sinus variously devel- 

 oped, sometimes a mere notch, with no overhanging rostral pro- 

 cess, sometimes rather large, and deep, with a distinct rostrum. 

 Outer tooth of second maxilla three-lobed, lobes plain-edged. 

 Furca with few ungues. 



Rutiderma rostrata no v. sp. 



PI. 20, figs. 8-13. 



Shell of female in side view nearly oval, rather distinctly 

 truncated behind and somewhat higher than in front; ventral 

 margin evenly arched; dorsal margin more boldly arched poste- 

 riorly; posterior margin slightly protuberant near the postero- 

 ventral angle; rostrum distinct, with an overhanging beak; an- 

 tennal sinus rather large and deep, opening downwards. The 

 margins of the valves bear cilia which are longest anteriorly. 

 A narrow, transparent marginal membrane extends from the 

 postero-ventral protuberance forward along the ventral margin, 

 thence along the anterior and dorsal margins to the anterior edge 

 of the hinge; this marginal membrane is fringed with minute 



