32 TRUE CRABS OF MONTEREY BAY 



Loxorhynchus crispatus Stimpson. 

 Plate V, fig. 15. 



Loxorhynchus crispatus Stimpson, Jour. Boston Soc. Nat. Hist., vi, 453, pi. xxii, 

 figs. 2, 3 and 4, 1857. Rathbun, Proc. U. S. Nat. Mus., xvii, 74, 1894. Holmes, 

 Occas. Papers Calif. Acad. Sci., vii, 30, 1900. Rathbun, H. A. E., x, 175, 1904. 



A series of 30 specimens (9 young) correspond well with Holmes's 

 description, to which, however, the following points may be added. The 

 anterior branchial tubercle is double, due to a smaller tubercle arising 

 from the anterior internal flank. About midway between the posterior 

 branchial tubercle and the cardiac-intestinal ridge, and lying nearly par- 

 allel to the latter, is a short slightly curved ridge or elongated tubercle. 

 The tubercles of the carapace and of the legs, appearing, according to 

 Miss Rathbun, "hemispherical with small shining points emerging," are 

 in young or perfect specimens topped by a bunch of long clavate setae, 

 stouter and longer than those of the rostrum and uncurved. Similar 

 setae are found along the angles of the somewhat prismatic legs, along 

 the posterior margin of the carapace, about the coxae of the legs, and 

 along the edge of the abdomen in the female. 



The chelipeds of the male, as stated by Miss Rathbun, gape at the 

 base and the dactyl is provided with a blunt tooth which projects into 

 this space, while those of the female meet throughout their length. 



The young (13 to 22 mm.) differ considerably from the adults, the 

 inner layer of plush-like hair being less marked, while more long hairs 

 are scattered over the surface; the preorbital spine is more flattened at 

 the base and directed more nearly horizontal, while the distance between 

 their tips and the length of the rostrum in proportion to the length of the 

 carapace is much greater than in the adult. Width between tips of pre- 

 orbital spines is to length of the carapace as I is to 3 in young and as I 

 is to 5 in an old male. The tubercles in the young are less pointed and 

 prominent than in the adult. Intermediate stages, however, connect all 

 these characters. The horns of the rostrum are more divergent in the 

 female than in the male. 



The color of specimens in alcohol ranges from reddish brown to tan ; 

 the carapace after removal of the hair often shows red markings, espec- 

 ially about the tubercles. 



