ANOMOURA J1GLEIDEA. 477 



and areas lettered ; c, side view of carapax ; d, extremity of abdomen ; 

 e, sternum; /, branchiae. 



In shallow fresh-water streams, Chili, from beyond the Cuesto del 

 Prado, on the road from Valparaiso to Santiago, sixty miles from the 

 sea ; abundant, swimming generally over the bottom. Collected, April, 

 1839. 



Length, one and a half to two inches. Colour, olive-green. Cara- 

 pax depressed, posterior angles rounded, a little pubescent in some 

 parts, crossed by a transverse suture ; in anterior region a U-shaped 

 depression, in posterior, longitudinal sutures dividing the surface 

 across into three nearly equal areas; also, a submarginal suture either 

 side ; antero-lateral margin bi-emarginate, extraorbital spine promi- 

 nent, acute, with a small tooth on inner side near apex, beak acute cari- 

 nate above. Eyes rather shorter than beak. Anterior feet very stout. 

 Hands unequal, right one the larger, very broad, half as broad as 

 carapax, subrhomboidal, surface somewhat scabrous, outer margin 

 nearly entire, inner margin anterior to finger, short, somewhat com- 

 pressed and dilatate; finger and thumb denticulate, inner margin 

 trenchant; carpus and arm three-sided, within acutely dentate, and 

 dentato-costate above. 



Abdomen laterally pubescent, and sometimes slightly pubescent 

 throughout. Seventh segment not half as broad as preceding, subtri- 

 angular, obtuse, having a longitudinal suture, and a slight emargi- 

 nation at apex, ciliated, caudal appendages either side make the 

 caudal extremity as wide as preceding segment ; basal joint lamellar, 

 oblong transverse, broadest anteriorly; lamellae obovate, ciliate, inner 

 one the larger. 



Sternum triangular, the anterior piece very narrow; the pieces 

 gradually increase in width backward, the four anterior pieces of 

 equal length, each a very short trapezium in form. Fifth piece very 

 short, and consisting of a medial portion and a lateral, the lateral 

 much smaller than the medial. 



First antennae have the flagella not half as long as base, the stouter 

 one ten-jointed, joints transverse, and a few short hairs at inner apex 

 of each; the other flagellum extremely slender, ten-jointed, naked. 

 Second joint of base arises laterally from inner side of first, oblong ; 

 third joint a little shorter than second. The base when extended 



120 



