350 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



Diagnosis. — Sides of carapace arcuate. Basal antennal article 

 with a longitudinal groove parallel to its outer margin. Two rows 

 of deep excavations on arm. Ridges and margins of ambulatory legs 

 thickened; upper margin of merus spinous. 



Description. — Of larger size than T. puella; antero-lateral margins 

 more convex; areolations and berry-like tubercles less strongly marked. 

 Rostral horns contiguous, tips beadlike. The basal article of the 

 external antennae is exposed from above, and bears two anterior 

 teeth or lobes; it is separated from the fronto-orbital region by a deep 

 suture or pit, and there is also a deep pit on the upper surface of the 

 spine or tooth at its exterior angle; below, a shallow groove runs 

 parallel with the outer margin. The first two movable articles of the 

 antennae are broad and pitted, the remainder are very slender. 



The merus of the chelipeds has two longitudinal but not contiguous 

 rows of deep excavations; hands carinate beneath; in the adult male 

 the fingers are very slender, the excavate tips are shorter than in 

 puella, and the large tooth of the dactylus is near its middle and is 

 slender, as long as it is wide. Both fingers more or less denticulate 

 within. Merus of legs deeply bisulcate longitudinally by blunt 

 ridges and armed along the superior margin with a series of strong, 

 short spines which are not concealed by the thick hair; the proximal 

 spine of the row is out of line and situated on the posterior surface 

 instead of on the margin and is a conspicuous feature in the legs of 

 the first three pairs; lower limb of merus narrower than in puella 

 and with thickened margin; both margins fringed with hair. Superior 

 margin of carpus thick, arcuate, inferior margin unilobate. 



Color. — Chelipeds, in alcohol, a bright, shining carmine tint 

 (Lockington) . 



Measurements. — Male (47121), length of carapace 15.1, width of 

 same 14 mm. Length of type-specimen 22.8 mm. {-^ inch) . 



Range. — West coast of Mexico from Gulf of California (Tepoca 

 Bay) to State of Oaxaca. 



Material examined. — 



Tepoca Bay, Sonora, Mexico; April 25, 1921; Fred Baker, Cali- 

 fornia Academy Exped.; 1 male (Cal. Acad. Sci.), with chelipeds 

 not fully developed. 



San Francisquito Bay, east coast Lower California; beach; April 9, 

 1911; Albatross; 1 male (55767). 



Mazatlan, Mexico; A. Agassiz; 3 males, 2 females (2097, M. C. Z.). 



Cape St. Lucas, Lower California; John Xantus; 9 males, 3 females 

 (1222, M. C. Z.). 



Puerto Angel, Oaxaca, Mexico; 1910; C. R. Orcutt; 2 males (47121). 



