68 BULLETIN 138, UNITED STATES NATIONAL MUSEUM 



Doubtful occurrence. — California : 21^ miles south of mouth of 

 Soledad Valley in the sea cliff. On the La JoUa topographic sheet, 

 due west of half way between the '' p " and '' u " in Pueblo (south of 

 mouth of Soledad Valley) in sea cliff facing ocean. Eocene series. 

 A carapace slightly larger than the type is embedded in friable rock ; 

 it is referred with much uncertainty to C. minor., as very few details 

 can be made out. 



Genus PORTUNITES Bell 



Portunites Bell. Monog. Fossil Malac. Crust. Great Britain, 1857, p. 20; 

 type, P. incerta Bell. 



Carapace little broader than long, depressed ; front dentate ; orbits 

 large; antero-lateral margin four or five toothed, posterior tooth 

 longer; branchial region with a blunt longitudinal ridge, against 

 which the last leg lies when raised above the carapace. Chelipeds 

 stout, of moderate length. Ambulatory legs slender, not natatory. 



Eocene; Oligocene. 



KEY TO THE PACIFIC SLOPE SPECIES OF THE GENUS PORTUNITES 



A\ Carapace wide ; width, measured in front of spine at lateral angle, one and 

 one-half times length. Orbit deep : length of outer orbital tooth on its 



inner slope as great as its basal width alaskensis, p. 72. 



A^ Carapace narrower ; width, measured in front of spine at lateral angle, 

 one and one-third times length. 

 B\ Regions of carapace deeply separated. Gastric region deeply divided 

 into three subregions. No very prominent tubercles near inner angle 



of branchial region. Size small insculpta, p. 71. 



B'. Regions not deeply separated except at middle of carapace. Two very 

 high tubercles in an obliquely longitudinal line near inner angle of 

 branchial region. Size larger triangulum, p. 68. 



POHTUNITES TRIANGULUM, new species 



Plate 17, figs. 3-0 



DescnpHon. — Outlines of carapace (pi. 17, fig. 5) : The lateral 

 .spine is located opposite the widest part of the mesogastric region; 

 it curves forward and upward, is acuminate and less than an eighth 

 as long as the width of the carapace at the sinus. Between the spine 

 and the orbital tooth there are three triangular acute teeth; the 

 second is acuminate and longer than the first, and the third, next 

 the lateral spine, is stouter than the others. The orbit is equal in 

 width to half the interorbital distance, its upper margin is crenulate, 

 interrupted by two fissures, the intervening margin truncate; its 

 inner angle is a short, acute tooth. The front proper is four-toothed, 

 a little advanced bevond the orbital angles, teeth acute, middle pair 

 slightly more produced than the outer pair, interspaces broadly 

 U-shaped, the median sinus narrower than the submedian. Pos- 



