OXYSTOMATOUS AND ALLIED CRABS OF AMERICA 5^37 



mesial carina; sixth segment oblong-quadrate, posterior margin armed 

 with a strong tooth pointed backward. Chelipeds very irregular, arms 

 tuberculate and granulate; hand nearly as broad as long, distinctly 

 carinated on outer side; dactylus with a lobe at proximal end of upper 

 carina. (After Bell.) 



Female: Much broader than male; in young as well as old, the eleva- 

 tions are found to be as numerous as in the young male described above. 



Color. — Pale brown; hollows of carapace gray; four minute red dots 

 on abdomen. (Bell.) 



Measurements. — Type male, length 18, width 15 mm. Adult 

 female (22132), entire length 11.7, width 14 mm. Young female 

 (22133), entire length 7.5, width 8.6 mm. 



Range. — West coast of Mexico to Ecuador; 2 to 51 fathoms. 



Material examined. — See table 42, page 138. 



LITHADIA CADAVEROSA Stimpson 



Plate 38, Figures 3-6 



Lithadia cadaverosa Stimpson, Bull. Mus. Comp. Zool., vol. 2, p. 159, 1871 

 (type localities, west of Tortugas, 35 fathoms, and off Conch Reef, Fla., 

 40 fathoms; types not extant). — Rathbun, Bull. Lab. Nat. Hist. State 

 Univ. Iowa, vol. 4, p. 293, 1898. 



Diagnosis. — A narrow median carina of granules. Rostrum 

 slightly concave. Highest points of carapace the branchial regions 

 which are almost entirely swollen. 



Description. — Carapace broad, suboctagonal, very little produced 

 posteriorly and strongly convex; branchial regions much swollen 

 especially in female. These regions and the other protuberant parts 

 of the carapace are more or less covered with depressed, often con- 

 fluent granules, arranged in lines or groups with depressed spaces 

 intervening, giving to the surface an eroded or vermiculated appear- 

 ance. Excavations between regions very deep, those surrounding the 

 cardiac region dotted with flat granules irregularly placed ; those sur- 

 rounding hepatic region and lying in front of branchial very narrow. 

 Hepatic region narrow, with a granulated ridge extending inward a 

 short distance from the anterolateral margin, which is here defined 

 by a similar ridge. Pterygostomian prominence triangulate. Be- 

 hind the hepatic region and separated from it by a deep transverse 

 sinus below, there are on the anterolateral margin of branchial region 

 two strong, triangular, flattened teeth pointing downward; the 

 anterior of the two is the larger. Posterolateral tooth of brancliial 

 region triangular in male, shallower and rounder in female. Intes- 

 tinal projections lobiform, shallow. One or two rows of small 

 tubercles on lower surface of branchial region. Front thick, sUghtly 

 concave. Chelipeds rugose, with angular, granulated protuberances; 

 merus subcylindrical. Ambulatories armed above with short thick 

 spines: last two articles somewhat setose. (After Stimpson.) 



