MAIOIDEA. 

 From California. William Kich, Esq. 



Length of carapax, one inch and eleven lines ; breadth between tips 

 of teeth across stomach region, one inch and three and a half lines ; 

 breadth between tips of teeth across cardiac region, one inch and five 

 lines ; length of anterior legs, three inches and five lines. 



In the specimen before us, the eight posterior legs are mutilated. 

 The third joint of the second pair is slender subcylindrical, not at all 

 carinate, and measures one inch and one line long. The pterygosto- 

 mian region has three small spiniforrn teeth. The first joint of the 

 outer antennae has a tooth on the outer side near middle. The 

 tubercles of the carapax, the more unequally-lobed alate expansion 

 behind the eyes, and the form of the anterior legs, distinguish this 

 species readily from the preceding. This species is named in honour 

 of its discoverer, the Botanist of the Exploring Expedition. 



SUBFAMILY MEN^ETHIN^E. 

 GENUS MEN^ETHIUS. 



The specimens of this genus collected by the author have the 

 following characters in common, in addition to those stated as generic 

 by Milne Edwards. 



Carapax subtriangular. Beak narrow and edged with short curled 

 setae, simple, sometimes emarginate at apex. Praeorbital spine elongate, 

 subacute. Sides of carapax with three largish teeth, the two anterior 

 often bilobate, so as to make in such cases five teeth alternately un- 

 equal. Surface of carapax more or less uneven or tuberculate. Cardiac 

 region prominent and showing at top three small tubercles triangularly 

 placed ; one or two small prominences between the cardiac protube- 

 rance and the lateral spine, forming a nearly straight range across the 

 carapax. The medial region is prominent, with two tubercles ante- 

 riorly, often nearly coalescent into one, and usually having anteriorly a 

 small tuft of setae ; also another tubercle posteriorly, or else three small 

 tubercles placed triangularly. Behind the cardiac prominence often a 

 small tubercle ; and posterior margin of carapax either entire or with 

 a small prominence near base of posterior legs and sometimes another 

 medial one. 



Eyes project laterally but little. Tmmovoable basal joint of the 



