MAIOIDEA. 125 



MEN^ETHIUS INORNATUS. 



Carapax latus, latitudine tram-orbitali dimidio minore quam sive latitudo 

 maxima sive longitudo post-rostralis, pane oculos non constrictiw ; mar- 

 ginibus lateralibus $-dentatis, dentibus triangulatis subacutis ; rostro 

 brevi, integro; spind prceorbitali lat& triangulatd ; superficie dorsali 

 paululum gibbosd, regione cardiacd simplicissime' tuberculatd, me- 

 diand tumidd, vix subdivisd, regione laterali fere pland. Ocidi parce 

 salientes, apice bene truncati. 



Carapax broad, trans-orbital breadth half less than either the greatest 

 breadth or post-rostral length, not constricted behind the eyes; 

 lateral margins with three low triangular teeth, which are some- 

 what obtuse or subacute ; beak short, entire ; praeorbital spine 

 broad triangular ; dorsal surface, but slightly gibbous, the cardiac 

 region with a single simple tubercle, the median tumid and hardly 

 subdivided into three parts, the lateral nearly flat, and not plicate. 

 Eyes sparingly salient, truncate at apex. 



Plate 5, fig. 3 a, male, enlarged three diameters ; b, under view of 

 head, six diameters; c, part of antennas, right side; d, under view of 

 eye ; d' ' , upper view of extremity of eye. 



Dredged at Lahaina, Hawaiian Islands. 



Length, five lines; exclusive of beak, four lines; greatest breadth, 

 four lines; trans-orbital breadth, two lines. The specimen examined 

 was without legs. The carapax is peculiar in having its breadth 

 across the eyes as great as half its post-rostral length ; and also having 

 no constriction behind the eyes, and in having few tubercles, and but 

 very slight undulations on the lateral region. The lateral teeth, 

 moreover, are nearly acute, and each is tipped with setae. The apex 

 of the third joint of the outer antennae projects as far as the apex of 

 beak, or even beyond it. The eyes are singular in their truncate cha- 

 racter, and a slight tumidity at the anterior and posterior apex. The 

 carapax rather abruptly declines back of a line that crosses by the 

 cardiac tubercle. 



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