3o8 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Order THORACOSTRACA. 

 Suborder DECAPODA. 



Tribe BRACHYURA. 

 Uca brevifrons ( Stim-pson). 



Plate XXXV, Figs. 1-5. 



Gelasimus brevifrons Stimpson, Ann. N. Y. Lye. Nat. Hist. v. 7, p. 229, 



i860. Smith, Trans. Conn. Acad. Sci. v, 2, p. 131, 1870. Lockington, 



Proc. Calif. Acad. Sci. v. 7, p. 148, 1877. 

 Gelasimus vocator Kingsley, Proc. Acad. Nat. Sci. Phila. 1880, p. 147 (in 



part). 

 Uca vocator Ortmann, Zool. Jahrb. Abth. f. Syst. 10 Bd. p. 352, 1897 (in 



part). 



Carapace convex, minutely punctated and microscopically granulated, the 

 branchial regions more or less plainly marked with small tubercles near the 

 outer edge; the H-shaped impression is prominent and the branchial regions 

 are marked with a faint longitudinal groove. Front broad, not strongly 

 produced forward. Upper edge of the superior margin of the orbit marked 

 with a prominent raised line, lower edge with a strong convexity midway 

 between the front and the lateral angles. Lateral angles almost right angles, 

 and slightly, or not at all produced forwards. Lateral margins of the cara- 

 pace for a short distance nearly parallel, arching slightly outwards, and then 

 converging quite strongly to the posterior margin. A conspicuous groove 

 just behind the anterior margin of the carapace extending from the sides 

 about halfway to the middle line. Orbital grooves deep, the lower margin 

 of the orbit curved from the inner end and furnished with short, rounded 

 spines which become larger around the outer angle. Eyes not reaching the 

 outer angles of the carapace. Merus of the external maxillipeds nearly as 

 long as wide, and f the length of the ischium, the lower margin but slightly 

 oblique. Merus of the large cheliped with the outer surface marked with 

 transverse, sparingly setose striae, the inner surface smooth; carpus long, 

 the outer surface roughened with small, blunt tubercles; inner surface 

 smooth, rhomboidal in outline, the upper margin armed with a few blunt 

 tubercles; hand large and stout, nearly twice as long as the width of the 

 carapace, upper surface with small tubercles which gradually become smaller 

 further down on the outer surface; upper margin of the palm raised, the 

 narrow space between this margin and the carpal groove tuberculated; 

 lower side of the palm marked with a fine raised line which fades out on the 

 base of the poUex; carpal groove moderately deep, continued anteriorly as 

 a shallow narrower groove to the base of the dactyl; the inner surface of the 

 palm is marked with a short, very prominent, tuberculated ridge which runs 

 from near the lower margin towards the supero-proximal portion of the 

 hand; from the upper end of this ridge there is a short tuberculated ridge 



