THE FOSSIL STALK-EYED CRUSTACEA 



125 



<iibital spine on the right side characteristic of the typical subgenus 

 (pi. 29, fig. 1 s) ; the tip is broken off but the spine is stronger than 

 in Recent species; the eyestalk is visible below, but it is detached and 



reversed. 



The third and fourth segments of the abdomen (paratype f) have 

 a groove setting off the anterior part of the lateral margin (pi. 30. 

 fig. 2) ; the adjacent surface bears a patch of very fine punctules 

 indicating hairs; the anterior angle is produced in a shallow lobe 

 which is rounded in the third segment, subacute in the fourth; the 

 sixth segment has sinuous lateral margins (pi. 30, fig. 1, 6), and is 

 widest across its middle. Telson (paratype /) coarsely punctate, a 

 deeply impressed median line. The inner appendage forming the 

 tail fan {ff, pi. 30, figs. 1 and 2) bears three smooth costae and the 

 outer appendage two. 



The chelipeds are equal (paratype a). The arm (paratype g) is 

 massive, surface wrinkled, distal end flattened dorsally in a tri- 

 angular surface. The wrist (paratype c) has a crenulated inner 

 edge, a :itoutish inner distal spine, a few smaller distal spines; the 

 dorsal surface has two longitudinal grooves meeting at the middle 

 of the distal end. Palm (paratype h) much swollen (pi. 30, fig. 3), 

 diminishing at the proximal end ; upper part of outer surface granu- 

 late ; inner surface with a longitudinal groove above, and below that 

 on the proximal three-fifths a series of eight oblique well-separated 

 stridulating ridges (paratypes e and A), an unusual arrangement in 

 the genus (pi. 29, fig. 2; pi! 30, fig. 1*) ; just proximal to those are sev- 

 eral tubercles; above the lower margin there is a smooth longitudinal 

 ridge in the upper slope of which are numerous punctules. The 

 immovable finger (paratype c) is short, slender, curved, deflexed 

 (pi. 30, fig. 4) and much smaller than the dactylus. The latter 

 (paratype b) is only partially exposed; it has a few large tubercles 

 on the upper edge, a groove through the middle, the lower edge of 

 which is granulate. 



Of the remaining pereiopods, the upper half of the outer surface 

 of at least two (paratype e) is granulate, granules more or less 

 arranged in short transverse ro\vs, upper surface punctate. 



Measurements.— Pnvsityi^e a, length of carapace in front of the 

 cervical suture 8 mm., length of palm 7 mm. Paratype A, length 



of palm 10.7 mm. 



Occurrence.— SYashington: Railroad bluff about IVs miles south 

 of Vader, Lewis County, about 700 feet below railroad post No. 79, 

 section 4, township 11 north, range 2 west; Eocene series; portions 

 of at least six individuals, one of which is holotype; in University of 

 Washington. 



