THE FOSSIL STALK-EYED CRUSTACEA 103 



than in the left chela where they are largely broken away. The 

 outer surface of the palms is strongly convex from the upper to the 

 lower margins, slightly so from end to end ; on the upper two-thirds 

 there are five rows of stout, spaced tubercles or blunt spines. The 

 upper row is marginal, the lowest of the five is prolonged feebl}'^ on 

 the fixed finger; the upper and lower interspaces are narrow, the 

 others wide, the second, counting from the top, widest ; the upper in- 

 terspace forms the upper surface of the palm. The lower margin is 

 marked by a row of similar tubercles, and above it is a partial row. 

 The remainder of the outer surface is deeply reticulated, with indi- 

 cations of low tubercles at the principal intersections of ridges. Im- 

 movable finger elongate triangular, very high at base. Dactylus 

 thick in top view, showing four irregular rows of tubercles. 



Right palm similar to left but a little lower and longer; distally 

 it is still lower as the outer surface there turns abruptly inward 

 forming a lower surface. 



Upper edge of merus of cheliped tuberculate, lower edge slightly 

 imbricate; outer surface largely covered with short, deeply im- 

 pressed lines. 



Measurements. — Holotype, greatest height of right palm 12.4 mm., 

 superior length of same 12.4 mm. ; greatest height of left palm 13 

 mm., superior length of same 10 mm., inferior length of palm and 

 immovable finger 21.6 mm., basal height of latter 7.8 mm., superior 

 length of dactylus 13.7 mm., extreme height of merus 8.8 mm. 



Occurrence. — California: vicinity of La JoUa; Eocene series; one 

 specimen, showing the two chelae of a single individual, side by 

 side; below the left palm is the greater portion of the merus, the 

 cheliped having been bent on itself at the middle. Holotype in 

 University of California. 



Relation. — In most Recent species of the genus Dardanus the left 

 cheliped is larger than the right, but seldom are the two so nearly of 

 a size as in this species. In D. hessii (Miers)^^ for instance, the 

 chelae are nearly or quite equal but much smaller and narrower than 

 in our species. The ornamentation of D. suhaequalis is akin to that 

 of the Japanese D. impressus (de Haan),*'' but here the armature 

 consists of sharp-pointed spines instead of blunt tubercles and the 

 chelipeds are very unequal. None of the species now living on the 

 American coast resembles this Eocene species. 



DARDANUS ARNOLDI, new species 

 Plate 24, figs. 5-8 



Description. — Dactylus: Two longitudinal rows of spines (pi. 24, 

 fig. 6), one on outer margin, the other on middle of upper side; 



*^Pagurus liessii Miers, Zool. Alert, 1884, pp. 185 and 264, pi. 28, fig. A. 



*^ Pagurus impressus de Haan, Fauna Japon., Crust., 1849, p. 207, pi. 49, flg. 3. 



