THE FOSSIL STAL.K-EYED CKUSTACEA 55 



length. Outer surface of merus finely punctate, a deep gutter run- 

 ning near and parallel to distal margin; on upper margin on pos- 

 terior border of gutter, a short blunt tooth (pi. 39, fig. 2) ; on lower 

 margin tAvo stout teeth near together, tlie one close to gutter is coni- 

 cal; further back on margin, not far from proximal end is a scar 

 which appears to be a cross section of another spine. Upper surface 

 of carpus finely granulate, spine at inner angle short, stout, blunt, 

 recurved; outer surface with four, possibly five, rows of large 

 tubercles, four tubercles in each of the three upper rows. Only 

 three smaller tubercles are visible in the fourth roAV at the proximal 

 end; a break in tlie shell obscures the remainder, also a possible 

 fifth row. Tliere is a trace of a distal gutter ; there is also a shallow 

 longitudinal depression separating the second from the third row of 

 tubercles. Manus thick, outer surface very convex from end to end as 

 well as from top to bottom. On the short upper margin there is a 

 line of three or four tubercles; on proximal half of outer surface 

 five tubercles forming a V the arms of w^hich diverge widely from 

 the apex situated low" down near carpus; a row of five tubercles on 

 proximal three-fifths of lower margin. Distal margin of manus 

 oblique. Fingers thick but rather narrow, widely gaping; tips 

 broken off, that of the dactylus indicated by the corresponding de- 

 pression ; propodal finger horizontal. 



Measurements. — Merus, length through middle 16 mm., distal 

 width 15.1 mm. Carpus, superior length 16.6 mm., width measured 

 just behind inner spine 14.2 mm. Manus, length from just above 

 immovable finger to lower proximal angle 24 mm., horizontal length 

 through middle 19.4 mm., superior length 11.9 mm., width (or 

 height) 20.2 mm. Dactylus, length 22 mm., greatest or proximal 

 height 8 mm. Immovable finger, height at its origin about 6 mm. 



Occuii^ence. — California : Kellys Ranch, 5 miles north of Carlsbad 

 Station, Santa Fe Railway, San Diego County; Cretaceous. Holo- 

 type. Cat. No. 73390, U.S.N.M. 



RelatiGn. — While this cheliped has the general form of a Zanthoj)- 

 sis, it differs from all other species of which the cheliped is knoAvn 

 by the greater number and different disposition of tubercles. 



Genus LOPHOPANOPEUS Rathbun 



Lophopanopetis Rathbux, Bull. Labor. Nat. Hist. State Univ. Iowa, vol. 4, 

 1898, p. 272; tyi)e, L. bellus (Stimpson). 



Carapace hexagonal; fronto-orbital border half or more than 

 half greatest width of carapace; front short, divided into two sinu- 

 ous lobes; postorbital tooth small, more or less coalesced with the 

 next tooth; remainder of antero-lateral margin more longitudinal, 

 cut into three prominent teeth. Palm short, swollen; immovable 

 finger short, rapidly tapering, dactylus narrower and longer, both 

 fingers pointed. Ambulatory legs more or less cristate. 



