182 University of California Publications in Zoology [Vol. 23 



legs, and on under parts, becoming bluish, white on sternum. Flagella of antennae 

 transparent elaret color. Larger scale-like projections of rugae on anterior portion 

 of carapace and chelipeds spotted with brick red, the two to three spots of red 

 to each of the scales on the carapace giving it an apparently tuberculated appear- 

 ance. Hairs yellowish. A few scattered spots of brick-red occur on the first 

 few abdominal segments. 



Type Locality. — San Clemente Island, California (H. N. Lowe). 



Distribution. — There are specimens in the United States National Museum 

 from Monterey, Santa Monica, and San Pedro bays, and Santa Rosa, San Clemente, 

 and Santa Catalina islands. I have also seen a specimen collected at Laguna Beach 

 by Prof. W. A. Hilton of Pomona College. 



Bemarlcs.— This species has been named in honor and appreciation of Dr. Mary 

 J. Rathbun, associate in zoology of the Smithsonian Institution. 



In general appearance and coloration it resembles P. agassizii Faxon (Bull. 

 Mus. Comp. Zool., 24, 174, 1893; Mem. Mus. Comp. Zool., 18, 69, pi. 15, fig. 1, 

 1895), but it is readily distinguishable in that it lacks the three teeth which are 

 so prominent on the anterior border of the carpus of the chelipeds of that species. 



Tribe BRACHYURA 



Key to the Subtribes of the Brachyura 



I. Mouth-field (endostome) triangular, narrowed in front, produced forward 



over epistome to form a gutter; efferent branchial channels opening at 



middle of endostome; third maxillipeds more or less narrow, not expanded 



into flat, lid-like structures as in other crabs.- Carapace more or less 



circular. Female openings generally on sternum. First pleopods wanting 



in female. 



Oxystomata, p. 185. 



II. Mouth-field roughly square. 



A. Last pair of legs abnormal, small, and subdorsal in position, as are 



often also the legs of the fourth pair. Antennae long, flagellum 

 equal to more than one-half width of carapace; antennules without 

 special fossettes; sometimes a common orbito-antennulary fossa pres- 

 ent. Female openings coxal. First pleopods present in female. 



(Not known north of Monterey Bay.) 



Dromiacea, p. 182. 



B. Last pair of legs normal, rarely reduced, not dorsal. Antennae short, 



never equal to one-half width of the carapace; antennules usually 



lodged in special fossettes. Female openings sternal, rarely coxal. 



First pleopods wanting in female. 



Brachygnatlia, p. 191. 



Subtribe DROMIACEA 

 Key to the Superfamilies and the California Families of the Dromiacea 



I. Sternum of female with a pair of obliquely longitudinal grooves.' Eyes and 



antennules almost always retractile into common orbito-antennulary pits. 



Rudimentary uropods usually present. (Superfamily Dromiidea.) 



Dromiidae, p. 183. 



II. Sternum of female without longitudinal grooves. Eyes not retractile into 



orbits nor antennules into pits. Uropods never present. (Superfamily 



Homolidea.) _ ... „ 00 



Homolidae, p. 183. 



