442 The University Science Bulletin. 



than the Kansas forms, more robust, with front femur relatively- 

 thicker and possessing a more or less well-marked sinuosity near the 

 inner apex, with antennae which, on the whole, are blunter at tip, 

 and the subapical tooth of the claspers of male slightly more slen- 

 der, it seems wise to consider them a variety, for which I propose 

 the name Ranatra kirkaldyi var. hoffmanni. It will be noted that 

 Mr. W. E. Hoffman has provided me with the longest series of this 

 variety. In a series as large as this, it would seem that if the variety 

 were not fixed there should be found forms like the true kirkaldyi, 

 which is described as having "anterior femora broad with a promi- 

 nent tooth near the middle, otherwise smooth." 



Ranatra buenoi, sp. new. 



= R. fusca Bueno, Can. Ent. XXXVII, p. 188, 1905. 



Bueno and Brimley, Ent. News, XVIII, p. 438, 1907. 



Bueno, Ent. News, XXXII, p. 273, 1921. 



Montandon ; determination in U. S. National Museum. 



Size. Length from tip of beak to tip of abdomen, 32 mm. to 38 mm.; caudal 

 filaments, 22 mm. to 27 ami. long.. 



Color. From light to very dark fuscous; top of abdomen orange and black; 

 middle and hind legs of lighter forms banded. 



Shape. Long and slender, prothorax long and slender; eyes very prominent 

 and large; limbs all very slender and very long; the under side of prothorax 

 with a single broad and deep sulcus, which distinguishes this species from any 

 of our other forms (see fig. 6, pi. XLVIII). 



Structural peculiarities. The eyes very prominent, transverse diameter 

 greater than the interocular space; tjdus longer than jugae and as prominent 

 as these parts, which are of medium development; antennae with the lateral 

 prolongation of penultimate segment not more than half the length of ulti- 

 mate; prothorax slender, the anterior portion measured on the median dorsal 

 line, twice the length of the posterior swollen part (the well-marked long trans- 

 verse lateral grooves used as di\ading line) ; scutellum somewhat elevated and 

 slender and the length of the abdomen is to pronotum as 2^ is to 1; respira- 

 tory filaments surpassing front margin of scutellum when brought forward; 

 claspers of male genital bulb very distinct; subapical tooth greatly reduced 

 (see fig. 1, pi. XLVI) ; all the limbs strikingly long and slender, especially the 

 anterior femora (see fig. 1, pi. XLVIII) ; no apical tooth on anterior femur, the 

 other tooth much nearer the apex than the base, the basal part being at least 

 IV2 times as long as the part lying before the tooth; the coxa two-thirds as 

 long as the femur. 



The middle and hind legs long, the distal ends of hind femora surpassing 

 the last abdominal suture and often nearly attaining caudal end of genital 

 segment, while the middle femora frequently attain or surpass the caudal 

 margin of penultimate abdominal segment; the distal ends of middle and 

 hind legs almost attaining tip of respiratory filaments; the relative lengths 

 of femora to tibiae are about as 16 is to 19 for the middle leg and as 16 is to 

 22 for hind leg. The tarsi are small relatively, a little less than one-sixth as 

 long as their tibiae. 



