ACADEMY OF SCIENCES. 



97 



Aterijatis cristatissimo. Lockington. Proc. Cal. Acad. Sci., March 20, 1876. 

 La Paz, San Jose Island, Amortiguado Bay. 



This pretty little species does not appear to occur on the west coast of Low- 

 er California. 



The color of the carapax in spirits is the same as in the dried specimen, 

 viz., bright red. 



No. 30. Two males, dried. From La Paz. D. E. Hungerford. 



No. 42. Male and female, in spirits. "W. N. Lockington. 



Actcea meandricus. nov. sp. 



Front four-lobed, antero-lateral margin without conspicuous teeth; postero- 

 lateral margin highly concave. 



Entire upper surface of the carapax covered with involved rugae; those of 

 each areolet distinct; areolets separated by sulci. 



Chelipeds equal, their upper outer surface rugose like the carapax, the 

 rugae giving way to rows of tubercles on the underside of the manus. 



Upper edge of the manus and carpus an acute angle; inner surface of both 

 perfectly smooth; rneros smooth on both sides, compressed. 



Hinder limbs with compressed joints; the meros smooth on both sides, ex- 

 cept in the fifth pair; the remaining joints rugose on their upper and posterior 

 aspects. Meros of fifth pair rugose above. Fingers of chelipeds sulcate, 

 short. Sternum cavernous; abdomen with transverse ruga?. Color, in spirits, 

 dull red. 



Locality, Mulege Bay, Gulf of California. 



Two specimens, a male and female, are all I have seen of this well marked 

 species. 



M. M. M. M. 



Greatest length - 20 19 



Extreme width of carapax 27 25 



This little crab has a peculiarly compact appearance. The rugosities of its 

 limbs are so arranged that when they are folded up close to the carapax not a 

 portion of smooth surface can be seen either above or below, the only smooth 

 portions being lateral and hidden. 



Heteracicea. nov. genus. 



Form of carapax as in Actcea, but with an external hiatus to the orbit, and 

 its lower margin divided into two lobes. Abdomen of male, five-jointed. 



I am loth to form a new genus for a species which resembles an Actcea so 

 closely in its general aspect and form, which, in my belief, afford far better 

 evidence of the real affinities of any animal than are afforded by variations in 

 the form of the orbit or the length of the basal joint of an antenna; but I 

 have no choice in the matter, as the genus Actcea is denned as " without an 

 external hiatus to the orbit," while the genera with the lower margin of the 

 orbit divided into teeth have a seven-jointed abdomen in the male. 



Heteractcea pilosus. nov. sp. 



Aspect that of an Actcea, but the orbit with an external hiatus, and its 

 lower margin divided into two separate lobes. Front two-lobed, upper mar- 



