THE FOSSIL STALK-EYED CRUSTACEA 123 



the outer surface; the inner one is wider and tapers gradually to a 

 Doint at tip of finger, its surface is transversely concave and forms 

 a very oblique angle with the inner surface. Lower edge irregu- 

 larly dentate, teeth short witli blunt tips; distal to each tooth on 

 the proximal three-fifths of the margin there is a puncta or hole 

 for the insertion of hairs; on the distal two-fifths of the finger the 

 marginal line of punctae is continued on the outer surface close to 

 the margin by four punctae; a little further from the edge there is 

 ;i row of five punctae confined to the proximal two-thirds ; near the 

 upper edge not far from the top there is a single pinicta. Tlie upper 

 edge of the outer surface where it bends abruptly inward is marked 

 by a line of irregularly spaced punctae which are larger on the distal 

 half ; this edge has also at its proximal end a line of a few granules. 

 The prehensile edge is concave except for a broad, shallow lobe 

 proximal to the middle, as above stated; it is rough with about 36 

 small but irregular and crowded tubercles. The margin between 

 the inner and the oblique upper surface has about 16 tubercles on 

 ils proximal half, rest of margin smooth; among the tubercles are 

 two or more punctae the line of which is continued on the inner 

 surface by two additional punctae placed obliquely. The tip of 

 the finger is short and blunt and curved well upward. 



Dactylus or movable finger (pi. 18, figs. 7 and 8) : The largest 

 nncl most complete dactylus is among the type lot; it lacks the proxi- 

 mal end, all the material being very fragile. The outer surface is 

 very convex in both directions especially transversely; the inner 

 surface is concave in a longitudinal direction, and is bluntly ridged 

 through the middle lengthwise. Upper and lower edges convex, 

 converging to a point where the tip of the finger turns abruptly and 

 vertically downward. Prehensile edge bearing 21 larger and proxi- 

 inally seven or more smaller tubercles. Upper edge having small 

 blunt teeth gathered mostly in distant groups of two or three. On 

 the outer surface just below this margin are four large holes, and 

 a little farther above the lower margin three large holes unequally 

 spaced. On the inner surface the holes are smaller and five in 

 number ; two form a line across the middle, while a third makes an L 

 Avith these and is situated near distal end not far from prehensile 

 edge; the other two are submarginal near proximal lower end and 

 are socketed so as to direct the hairs upward. 



Measurements. — Holotype, left immovable or propodal finger^ 

 length on upper edge 12 mm., greatest width (at origin) 5 mm. 



Occurrence. — California; Pleistocene series: 



Nob Hill (lumber yard), northeast of San Pedro; Lower San 

 Pedro formation; 1 left movable finger, 14 immovable fingers, 3^ 

 right, 11 left; Cat. No. 358332, U.S.N.M. 



