90 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 47. 



*perplexum Smith, 1854. Georgia. Tab. 3. 

 Legs and margin of thorax ferruginous. 



This is to be referred to Dianthidium subgenus Anthidiellum on the authority of Mr. 

 Cra^vford. 

 placitum Cressoon, 1879. Nevada (Morrison). Tab. 2, 3. 



Female clypeus yellow except a median stripe; a yellow band behind ocelli, in- 

 terrupted in middle, 

 placitum praedentatum Cockerell, 1907. Boulder, Colorado (G. Hite). Tab. 2, 5. 

 *porter£e Cockerell, 1900. Las Vegas, New Mexico (W. Porter). Tab. 1, 5. 

 Trior to 1900 confused with A. macuKfrons. 

 Also in Texas, and north to Calgary in western Canada. 

 Type.— Cat. No. 5812, U.S.N.M. 

 *porterffi amabile Cockerell, 1904. Boulder, Colorado (Cockerell). Tab. 5. 

 Ground color of abdomen red. 

 Type.— Cat. No. 9655, U.S.N.M. 

 *porter» personulatum Cockerell, 1907. Boulder, Colorado. (W. P. Cockerell). 

 Tab. 5, 6. 

 Female clypeus entirely black; male with apical lobes and spine of abdomen black. 

 *poudreum Trrus, 1902. Fort Collins, Colorado (Titus). Tab. 2. 

 '^pondreum,'^ in the original publication, is a misprint. 



Male (11 mm.) differs from atrifrons by the yellow markings, scape entirely black, 

 and last abdominal segment deeply notched, with a blunt black tooth in middle. 

 Variety (? hybrid with tenuifiorsc); Ent. News, 1909, p. 262. 

 Also at Flagstaff, Arizona (Pratt). 

 praedentatum trianguliferum Swenk, 1913. Fort Garland, Costilla County, Colorado 



(L. Bruner). 

 *psoraleffi Robertson, 1902. Near Carlinville, Illinois (Robertson) Tab 6. 

 Characters: Trans. Amer. Ent. Soc, vol. 29, p. 175. 

 Face of female black. 

 p*ridingsii Cresson, 1878. Georgia (J. Ridings). Tab. 3. 



"A very distinct species, easily recognized by the abdominal fascise being very 



narrow and regular." (Cresson.) 

 This is to be referred to Heteranthidium on the authority of Crawford. 

 rodriguezi Cockerell, 1912. Guatemala (Rodriguez). 

 sagittipictum Swenk, 1913. Pullman, Washington (C. V. Piper), 

 saxorum Cockerell, 1904. Rock Creek, California (Davidson). Tab. 1. 



Abdomen shining, with sparse punctures, the markings orange, 

 scudderi Cockerell, 1906. Fossil in the Miocene shales of Florissant (Scudder). 

 serranum Cockerell, 1904. Rock Creek, California (Davidson) Tab 6. 

 Male 15J mm. Comparison with illustre and conspicuum; Ent. News, 1909, p. 262; 

 also Bull. Southern California Acad. Sci., Feb. 1904, p. 23. 

 *tenuiflor8e Cockerell, 1907. Boulder, Colorado (W. P. Cockerell). Tab. 5, 6. 

 Allied to emarginahan; female ventral scopa sepia brown, pale at sides; male with 



dark tubercles and scutellum. 

 Also in Montana and western Canada. 

 titusi Cockerell, 1904. Fort Collins, Colorado (E. S. G. Titus). Tab. 1, 5. 



Allied to emargmatum. 

 transversum Swenk, 1913. Ute creek, Costilla County, Colorado (H. S. Smith). 

 *tricuspidum Provancher, 1896. Los Angeles, California (Coquillett). Tab. 1,3. 



Titus (1906) gives a new description. 

 *utaliense Swenk, 1913. Logan, Utah. 

 Paratype.— Cat. No. 15260, U.S.N.M. 

 wallisi Cockerell, 1913. Peachland, BritLsh Columbia (J. B. Wallis). 

 Described in Canadian Entomologist, 1913, p. 13. 



