CYDNIDAE OF THE WESTERN HEMISPHERE — FROESCHNER 613 



Bolivia: Sara: No exact locality, Steinbach, 2 males, 2 females (Cam; MCZ), 

 Santa Cruz: Puerto Sudrez, 150 meters, Steinbach, Ace. 3845, 1 female (Carn). 



Paraguay: Gran Chaco, 260 kilometers west of Paraguay River, Nov. 10, 

 1936, A. Schulze, 2 females (JCL). Villarrica, September 1935, F. Schade, 1 male 

 (USNM). 



Discussion. — This species furnishes an excellent example of the 

 superficiality of the approach to genera that has been commonly 

 employed in many of the studies of the Cydnidae. On the basis of a 

 slightly more elongate shape and a lengthened labium, this species 

 served as the type of a monobasic genus. The genus has stood with 

 this single species for more than seventy years, even though several 

 really closely aUied species have been described during that period. 

 Many workers have been misled by such specific differences which 

 are more conspicuous in a superficial scanning of a few species at a 

 time than are the more important features of the trichobothria and 

 osteolar peritreme. But such results must be expected when workers 

 are interested in cataloging and describing all the forms possible — the 

 differences being accorded more importance than the similarities. 



Dallastellus (Dallasiellus) lugubris (StSl), new combination 



Plate figures 42, 43, 274 



Aethus luguhris Stai, 1860, p. 13. 



Geotomus obscurus Signoret, 1883, p. 39, pi. 2, fig. 147. New synonymy. 



Geotomus mgrocinctus Signoret, 1883, p. 40, pi. 2, fig. 148. New synonymy. 



Geotomus semilevis Signoret, 1883, p. 44, pi. 3, fig. 153. New synonymy. 



Geotomus pangaeoides Signoret, 1883, p. 45. New synonymy. 



Geocnethus reversus Barber and Bruner, 1932, p. 237, pi. 25, fig. 1. New synonymy. 



Diagnosis.— Within its subgenus this species may be recognized 

 by the small size (3.9-5.5) coupled with the presence of two or more 

 close-set setigerous punctures in front of eye on submargin of head 

 and two almost equally developed rows of mesocorial punctures 

 paralleling the claval suture. 



Description. — Male: Oval, broadest near midlength. 



Head: Length less than three-fourths width, 0.84(0.82-0.86) : 1.29 

 (1.26-1 .32) linterocular width, 0.77(0.76-0.80); anterior outline semi- 

 cu-cular, juga very slightly longer than clypeus and strongly narrowing 

 it apically; surface polished, unpunctate, and with famt, radiating 

 rugae; two to four close-set submarginal setigerous punctures im- 

 mediately in front of eye and usually two widely separated ones 

 beyond them; ocelli distmct, separated from eye by a space equal to or 

 slightly greater than their own diameter; juga ventrally and maxUlary 

 plate polished, impunctate. Antennal segments: I, 0.23(0.23-0.24); 

 II, 0.24(0.23-0.26); III, 0.30(0.29-0.31); IV, 0.35(0.35-0.36); V, 

 0.42(0.41-0.42). Bucculae about as high as labial II, evanescent 

 posteriorly ; labium reachmg between middle coxae. Labial segments : 



