566 CALIFORNIA ACADEMY OF SCIENCES. 



PSEUDOPINNIXA NITIDA (Lock). 



Pinnixa? nitida Lockiugtou, Proc. Cal. Acad. Sci. vii, p. 155. 



Carapax smooth, shining, a little over twice as broad 

 as long, longitudinally convex, transversely plane, the 

 sides evenly rounded; the anterior margin is straight; 

 the front is broadly triangular, short, much deflexed, not 

 at all projecting, and having a groove behind the margin. 

 Orbits nearly as wide as long, the inner hiatus wide and 

 partly filled by the base of the very minute antenna?. 

 Antennules obliquely (nearly transversely) plicated. 

 Epistoma very short, curved. Buccal area broadly sub- 

 triangular, rounded in front, the posterior portion covered 

 by a projection of the sternum. External maxillipeds 

 subtriangular, the ischium rudimentary; the meros is 

 large and has the portion nearer the mouth bent inward 

 at a considerable angle to the outer face ; the first joint 

 of the palp short and stout, the second oblong, the third 

 very small. Chelipeds rather short, moderately stout, 

 smooth ; the meros is not much longer than the carpus ; 

 hand a little compressed, the palm thickened and pro- 

 vided on the outer surface with two longitudinal lines of 

 short cilia; fingers scarcely as long as the palm, tooth- 

 less, and hooked at the tip; on the upper surface of the 

 mo\'able finger is a line of cilia which is roughened by 

 minute projections. Ambulatory legs ciliated on the 

 margins ; the first pair is stouter and a little longer than 

 the others and has the anterior surface of the meros smooth 

 and concave where it rubs against the chelipeds ; the next 

 two joints are stout; the tarsus is short, subc3dindrical 

 and curved, and tapers rapidly to an acute, corneous tip. 

 The third pair of ambulatory legs is a little shorter than 

 the second; both are more compressed than the first pair; 

 the tarsi are similar in all three pairs ; fourth pair very 

 short, not reaching the distal end of the meros of the pre- 



