AHT. 1 AMERICAN WASPS OF THE GENUS SCELIPHRON PORTER 9 



mesopleura below the bases of the wings. When the yellow has all 

 disappeared except that on the tegulae, we have the form described 

 by Fabricius as Sphex -fiavipes. Saussiire speaks of variations of 

 ■fiavi'pes in which there is present a yellow subalar mark and others 

 in Avhich the scutellum and Inetanotiim may have yellow fasciae. 



From a study of this series, it is evident that there is a gradual 

 variation from the serviUei form, with a large amount of yellow, 

 down to the -fiavipes variation, with no yellow except on the legs, 

 tegulae, and scapes of the antennae. While in a general way the 

 forms with the greatest proportion of yellow are more common in 

 the more southern localities, none of the different forms are restricted 

 to any distinct region. No essential structural differences are found 

 through the series. A detailed study of the "male genitalia have 

 shown them to be identical throughout the group. It is thus evident 

 that the entire group consists of but one species, which was first 

 described by Drury as caementarlum. 



SCELIPHRON ASSIMILE (Dahlbom) 



Pelopoeus assimilis Dahlbom, 1843, Hymen. Europ., vol. 1, p. Zi, no. 7, 



female, male. 

 Bceliphron caementarium Dbury, var. nicaragtianum Kohl, 1918, Annalen de>! 



Naturhistorischen Hof museums Wien, vol. 32, p. 118. 



Black and yellow, the yellow distributed as follows: Scapes of 

 antennae, rorsal region of prothorax, scutellum, uietanotum, tegulae. 

 a streak below the tegulae, usually a spot on each side of the pro- 

 podeum anteriorly and one at end, sometimes the ventral side of the 

 petiole, an irregular spot or spots on first dorsal abdominal segment, 

 and parts of legs. 



Female. — Head: Frons slightly concave, insertion of antennae 

 slightly elevated; anterior margin of clypeus bilobed or bidentate, 

 the lobes rounded; clypeus and frons covered with a dense golden 

 pubescence which is thinner or absent above antennae, and also with 

 numerous black to golden upright hairs; antennae slender, filiform, 

 the segments having the following relative lengths: 1/19, 2/4, 3/31, 

 4/23, 5/19, 6/15, 7/13, 8/12, 9/11, 10/10, 11/9,^12/10; scape yellow^ 

 bulb fuscous, remainder of antenna black, very minutely sericeous: 

 mandibles very dark ferruginous to fuscous, slightly hairy towards 

 base, with longitudinal lines and furrows; vertex, genae, and occi- 

 put not pubescent or only slightly so, but with numerous erect blaclc 

 to golden hairs, and weakly punctate. 



Thorax: Dorsal region of prothorax with a large yellow spot; 

 surface weakly punctate, covered with long erect, black to golden 

 hairs. Mesonotum black, hairy, densely punctate, and somewhat 

 striate, scutellum transverse, longitudinally striate, with a large yel- 

 low spot, hairj^; tegulae yellow; area just below tegulae yellow, rest of 

 3017—26 2 



