Studies of North American Bees 31 



arates this species at once, while the immaculate mesoscutum and 

 mesosciitellum further differentiate it. Of the two it is closest to 

 pudicum, with which it agrees in the spotted clypeus and the com- 

 plete though deeply emarginate bands on tergites 2-4. From D. 

 ulkei (Cresson) and D. consimilc (Ashmead) the restricted 

 amount of yellow on the legs, lack of yellow supraclypeal, vertical 

 or mesopleural spots, wholly black mesonotum and tergite 6, 

 mostly black clypeus, etc., are diagnostic. The male that is placed 

 here with the type female of siihparvum resembles the males of 

 parvum and simile very closely, and may possibly be a variation 

 of parvum, but seems to be distinct in the tuispotted mesoscu- 

 tellum, heavily carinate sixth abdominal tergite and somewhat 

 deeper emarginations on the sides of the median tooth of the 

 pygidium. These emarginations are not, however, nearly so deep 

 as in pudicum J*. The scarcely emarginate pygidium of idkei <$ 

 easily separates that species. 



Dianthidium (Dianthidium) pudicum (Cresson). 



1879. Anthidiuin pudicum Cresson, Trans. Am. Ent. Soc, VII, p. 



208, 3. 

 1907. Dianthidium pudicum Cockerell, The Entomologist, XL, pp. 99- 



100, $. 

 1907. Dianthidium pudicum Cockerell, Univ. of Colorado Studies, IV, 



p. 250, ?. 



A series of three females, collected at Worland, Wyoming, July 

 191 1 (L. Bruner), are referable to D. pudicum. They agree with 

 Cockerell's description of pudicum 5, only on the tibiae, especially 

 the middle pair, there is a tendency to have the basal spots pro- 

 longed in narrow stripes part way down the outer face and some- 

 times the lateral part of the light marks on tergite 5 is represented 

 by a small pale dot. With the three females is a male collected 

 at the same time, and a second male is from Ute creek, Costilla 

 county, Colorado, on sage flats, August 7, 1907 (R. W. Dawson). 

 As Cockerell has stated {Proceedings U. S. National Museum, 

 XL, p. 248) the male of D. pudicum can be separated from D. 

 parvum (^ by the deeper notches on the sides of the median apical 

 tooth of the pygidium. 



31 



