hungerford: aquatic hemiptera. 213 



asymmetry and strigil dextral; fifth tergite entire, sixth divided." — 

 Abbott. 



The above description is taken from Can. Ent. for April, 1913. This 

 is a revision of the original generic diagnosis. To date there have been 

 described two species separated by the following table. 



KEY TO SPECIES. 



a. General facies dark. Tegminal lineations complete. Front femur 

 of female oblong, 2V^ times as long as wide. Palar pegs of male 

 24-33* in crowded row the length of pala. P. bueuoi Abb. 



AA. General facies light. Tegminal lineations incomplete. Front femur 

 of female trapezoidal, two-thirds as wide as long. Palar pegs of 

 male in two rows confined to base of pala. P. gillettii Abb. 



Palmacorixa buenoi Abbott. 



Can. Ent., Apr. 1913. 



"Similar to P giUettei in size and appearance, in the flattened short 

 pronotum, and large head, with prominent posterior angles. Dark yellow 

 to smoky brown, and much darker than giUettei. The tegminal lineations 

 are complete, more or less inosculated and confused, but without a marked 

 tendency to longitudinal seriation. Lineations of clavus complete, i. e., 

 not eff^aced on the inner anterior area as in giUettei. Head smoky brown; 

 its length 1% in the width of the male, 2V4 in the female; interorbital 

 width twice in the head length in the male, 1% in the female. Male fovea 

 more prominent than in giUettei, reaching the middle of the eye, and 

 clothed with delicate depressed hairs. Pronotum flattened, margined, 

 lenticular in outline, evenly rounded posteriorly, dull and minutely 

 rastrate, with % approximately parallel lineations, which are more or less 

 broken, the lineations about as wide as the yellow interspaces. Posterior 

 margin brown. Claval lineations delicate, vermiculate and inosculate, 

 covering the whole clavus, fused externally to form a more or less definite 

 oblique line parallel to the corio-claval suture. Clavus rather infuscated 

 and clouded across the middle third. Markings of corium similar to 

 those of clavus, running without interruption over the membrane ; inoscu- 

 lated, but scarcely interrupted, sometimes fused into one or two rather 

 indefinite longitudinal lines, which do not extend beyond the embolium. 

 Surface of clavus and corium rather dull and rough, the clavus usually 

 rastrate, the corium merely punctate. Margins of embolium and of 

 clavus elevated. Lower surface and legs pale; posterior tibia fringed 

 with brown hairs. Metaxyphus very short, acuminate. Strigil rounded, 

 5 striae, diameter 0.1 mm. 



"Male pate cultrate, somewhat produced at the base, the length three 

 times the greatest height. Pegs blunt, elongate, 24-33 in number. The 

 distal ones are somewhat longer and crowded, and may be displaced into 

 two irregular rows. The main row begins midway the base and rises in 

 a curve after the first half dozen pegs ; then follows the upper margin, but 

 at some distance from it. A second row of peg-like spines along the 

 lower margin, about iy2 to 2 times the length of the pegs. Tibia sub- 

 globular, about as high as the pala. Femur oblong, a little less than 

 twice as long as wide, the stridular area covering the proximal half and 

 consisting of short spines set in transverse rows. Female palas cultrate, 

 not produced at base, slightly more than three times as long as wide, 

 broadly joined to the tibia. Tibia rounded oblong, tapered proximally, 

 twice as long as high. Femur oblong, 2V2 times as long as wide (the 

 width at base in P giUettei is two-thirds the length) with stridular 

 spines* on the surface as in P. giUettei. Second leg, Femur 2V2 times 



* Number of pegs exceeds this in one series examined by the writer. 



* Through a lapstis calami these are called "spines" in the description of P. r/iUettii 

 (1. c, p. 339). 



