428 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iii 



Specimens studied. — 2 males, 1 female. 



United States: New Mexico: No exact locality, Uhler collection, 1 female 

 (USNM). Texas: Colorado City, July 17, 1927, L. A. Stephenson, 1 male (KU). 

 Mexico: Distrito Federal: No exact locality, July 10, 1 male (Bon). 



Discussion. — The greatl}^ elongate labium reaching onto basal 

 sternites occurs in two other areas in the family as found in the 

 Western Hemisphere. In the Cydninae it appears on Dallasiellus 

 longulus (Dallas), while in the Amnestinae it may be found on one 

 species of Amnestus. 



Melanaethus cavicollis (Blatchley), new combination 



Plate figures 97, 208 



Geotomus cavicollis Blatchley, 1924, p. 85. 



Geocnethus cavicollis Hussey, 1925, p. 63. — Torre Bueno, 1939, p. 182. 



Diagnosis. — Within the genus, camcollis may be recognized by the 

 reduced size of the apical modification of the peritreme and the 

 number of coarse punctures present on most of anterior convexity of 

 proiDleuron. 



Description. — Male: Elongate-oval, widest posterior to mid- 

 length. 



Head : Length more than half width, 0.77 (0.72-0.83) : 1 .28 (1 .23-1 .37 ) ; 

 interocular width, 0.80(0.74-0.84); anterior outlme a flattened semi- 

 circle, clypeus as long as juga, narrowed apically; surface weaklj^ 

 convex, numerous distinct punctures arranged in radiating rows, 

 submarginal dorsal carina distinct only on apical half or less; ocelli 

 moderate, separated from eyes by space more than twice transverse 

 ocellar width; jugum ventrally polished, impunctate; maxillary plate 

 coarsely punctate except at base of antenna. Antennal segments: 

 I, 0.27(0.26-0.30); H, 0.36(0.32-0.40); HI, 0.38(0.36-0.42); IV, 

 0.43(0.40-0.47); V, 0.58(0.56-0.60). Bucculae higher than labial II, 

 abruptly sloping posteriorly; labium extending between middle coxae. 

 Labial segments : I, 0.44 (0.43-0.46) ; II, 0.75 (0.73-0.82) ; III, 0.55 (0.53- 

 0.60); IV, 0.40(0.40-0.42). 



Pronotum: Length more than half of width, L45(L36-L55):2.75 

 (2.52-3.04); anterior margin moderately, simply concave; lateral 

 margin straight to very weakly concave on middle third, with sub- 

 marginal row of four or five setigerous punctures; transverse impres- 

 sion almost absent, site marked by irregular row of coarse, widely 

 separated punctures; anterior lobe with coarse punctures clustered 

 behind each eye and in broad lateral band, middle half strongly 

 impressed for full length; posterior lobe coarsely, closely punctate 

 laterally and sparsely so medially. 



