438 PROCEEDINGS OF THE NATIONAL MUSEUIVI vol. in 



Length of body: 3.49(3.17-4.01). 



Type data. — The type male and paratype female (both in CalAc), 

 were taken at San Carlos Bay, Sonora, Mexico. 

 Specimens studied. — 14 males, 29 females. 



United States: Arizona: Atascosa Mt., Cochise Co., Douglas, Iligley, Mesa, 

 Oracle, Phoenix, Pima Co., Pleasant Lake, Thatcher, Yuma Co.; January, June, 

 July, August. California: Coachella, Davis, San Diego; January, May, July. 

 Idaho: Rupert; August. Neiu Mexico: Las Cruces; June. Texas: Presidio Co., 

 Valentine; July. Washington: Wilbur; March. 



Mexico: Sonora: Hermosillo, Pitiquito, San Carlos Bay; May, July. 



Discussion. — The placement of this species close to pensylvanicus 

 on the basis of the punctation of the head was not justified by the 

 material at hand. All material seen, including the female paratype 

 from San Carlos Bay, Sonora, showed distinct and often crowded 

 punctures on the head, not the minute punctation of pensylvanicus. 

 This is in contradiction to Van Duzee's original description which 

 reads, "superior surface minutely, obscurely, punctured." Compari- 

 son of specimens with the tj'pe will settle the question. 



Melanaethus subglaber (Walker), new combination 



Plate figure 213 



Aethiis subglaber Walker, 18G7, p. 150.— Torre Bueno, 1939, p. 181. 



MHanaethus elongatus Uhler, 1876, p. 280; 1877, p. 393; 1886, p. 3. New 



synonymy. 

 Geotomus parvulus Signoret, 1883, p. 208, pi. 4, fig. 170.- — Lethierry and Severin, 



1893, p. 72.— Bunks, 1910, p. 100.— Van Duzee, 1917, p. 22.— Torre Bueno, 



1939, p. 181. New synonymy 



Diagnosis.— Among the species of Melanaethus with the large 

 terminal modification of the peritreme extending almost to the lateral 

 margin of the evaporatorium, this one may be recognized by its very 

 elongate form and the fact that the transverse impression is distinct 

 across its entire width but not expanded medially. 



Description. — ^Male: Elongate-oval, slender for the genus, sides 

 parallel. 



Head : Length about three-fourths width, 0.63 (0.62-0.64) : 0.82 (0.80- 

 0.86); interocular width, 0.53(0.50-0.56); anterior outline elongate, 

 distinctly roundingly truncated, clypeus as long as juga, scarcely 

 narrowed at apex; surface, including clypeus, with numerous crowded 

 punctures; jugum with distinct marginal carina dorsally, with one 

 submarginal puncture anterior to eye; jugum ventrally shining, im- 

 punctate; maxillary plate alutaceous, feebly punctate. Antennal seg- 

 ments: I, 0.17(0.16-0.20); II, 0.18(0.16-0.20); III, 0.22(0.22-0.23); 

 IV, 0.27(0.26-0.30); V, 0.37(0.36-0.40). Bucculae higher than labial 

 II, abruptly terminated posteriorly; labium reaching between middle 



