72 BULLETIN 138, UNITED STATES NATIONAL MUSEUM 



palm (their tips are absent), they are equally broad at base leaving 

 a moderate gape and taper gradually toward the extremity. The 

 dactylus has a lon<r, stout, backward-pointing tooth at its base; three 

 other teeth are visible on the prehensile edge, they are short, blunt 

 and near together. The propodal finger is slightly deflected. 



Measurennents (approximate). — Holotype, length of carapace 12 

 mm., width at sinus in front of lateral spine 15.8 mm. 



Occurrence. — Oregon : Basket Point, Umpqua River, about 12 miles 

 below mouth of Calapooia River ; middle Eocene series ; one holotype 

 and impression and two paratypes, each represented by the dorsal 

 surface of the carapace in a small nodule; Cat. No. 353347, U.S.N.M. 

 Also from the same locality a small major chela in a nodule which is 

 referred to this species because the palm is of similar character 

 to that of the nearly related species, P. triangulum. 



Relation. — Nearly related to the type species of the genus, P. 

 incerta Bell,^* from the Eocene of the Isle of Sheppey, England. 

 In P. incerta the narrow part of the mesogastric region is not spatu- 

 Jiform, the metabranchial ridge is straight and not bounded out- 

 wardlj^ by a furrow, and the inner extremity of the branchial ridges 

 forms a more pronounced tubercle. 



From P. triangulum., this species may be distinguished by the 

 broader mesogastric region, the more prominent f)rotogastric lobes, 

 the deeper groove about the cardiac region. P. triangulum has a 

 triangle of three tubercles at the inner angle of the branchial region, 

 while in P. i7isculpta this arrangement is so obscurely indicated as 

 not to be noticeable. 



PORTUNITES ALASKENSIS, new species 



Plate 18, figs. 3 and 4; plate 22, fig. 3 



Description. — Outlines of carapace (pi. 18, figs. 3 and 4) : None 

 of the specimens shows an entire lateral spine and only one (N. Pac. 

 128) has the basal half preserved; this is subtriangular in outline and 

 points directly outward and very slightly upAvard. Orbital tooth 

 pointing forward, subacute, sides convex; next three lateral teeth 

 acute, sides concave, the .second one longest, the first one smallest and 

 close to the orbital tooth. Position of orbital fissures indicated only 

 by slight depressions in the surface; orbital margin finely crenulate. 

 Front narrow; two small submedian teeth separated by a V-shaped 

 emargination and follow^ed by a sinuous margin; outer angle sub- 

 rectangular, corner rounded off. A slight superior inner orbital angle 

 raised above level of front. Postero-lateral margin of carapace 

 sinuous ; posterior margin slightly incurved at middle. 



=*Monog. Foss. Malac. Crust. Great Britain, Part 1, London. 1S57 (1858), p. 21, pi. 3, 

 figs. 1-5. 



