44 bulletin: museum of compakative zoology. 



150 /j. ; legs normal, breadth of hind tibiae about 255 /x, of the basal joint of their 

 tarsi about 150 ; dorso- ventral diameter of abdomen about 1350 fi, length of head 

 about the same ; costa somewhat arched ; stigma large and black ; marginal 

 cell about 900 /x long and 195 wide, ending in a point on costa; first section 

 of b. n. about 150 ll long ; second section curved, fully 375 /j. long ; second s. m. 

 on marginal a little over 150 /x long, on cubital nervure slightly over 300, the second 

 t. c. curved outwards. 



Type. — No. 2011, Mus. Comp. Zool. Florissant, Col. (No. 1966, S. H. 

 Scudder Coll.). 



Lithandrena, gen. nov. 



A geuus of Andreninae, allied to Andrena. It differs from Andrena and 

 Nomia in the second r. n., which is strongly bent in its upper part, straight 

 but oblique below ; from Andrena it differs in the proportions of the submar- 

 ginal cells (see the dimensions given below) ; and from Nomia by the tip of 

 the marginal cell, which is pointed, and a little away from costa. The general 

 appearance is that of an Andrena, but it cannot be referred to that or any other 

 genus known to me. In Cresson's table it seems to run to Ceratina, but it is 

 not allied to that genus. 



Lithandrena saxorum, sp. nov. 



9 Length 8$ mm., anterior wing about 5^; diameter of thorax 3, head the same, 

 of abdomen 3J mm. ; head and thorax black ; abdomen light, with a broad entire 

 dark band on each segment ; legs hairy ; flagellum rather stout, diameter 195 fx. 

 In the following account of the anterior wing the measurements are in fx: stigma 

 well-developed, diameter 175, length of the part within marginal cell 360 ; marginal 

 cell long and pointed, length 1620, breadth 405, apex pointed, away from costa, but 

 distance from apex to opposite point on costa scarcely 65 ; three submarginal cells ; 

 total length of first s. m. 900, but its length on cubital nervure only 570, the first 

 t. c. being remarkably oblique, and having its lower part curved ; length of second 

 s. m. on cubital nervure 615, but it is greatly narrowed above, its length on mar- 

 ginal being only 150; first r. n. joining second s. m. 90 from end; length of third 

 8. m. about 675, but it is greatly narrowed to marginal, its length above being 

 about 270 ; second r. n. with a strong bend at the end of the upper two fifths, 

 the lower three fifths straight; length of first discoidal cell 1650 ; b. n. meeting 

 t. m. ; lower section of b. n. slightly curved (but not more so than in some forms of 

 Andrena), and more than twice as long as upper one (length of lower section 630, 

 of upper 300) ; t. m. oblique, its lower end more apicad (as in Andrenines, Pan- 

 urgids, etc.) 



Type.—TXo. 2012, Mus. Com. Zool. Florissant, Col. (No. 8219, S..H. 

 Scudder Coll.). 



Andrena sepulta, sp. nov. 



9. Length 9 mm.; width of thorax 2\ mm., of head and abdomen about the 

 same ; abdomen of normal shape ; flagellum stout ; there is an appearance as if 

 the eyes nearly met on the vertex, but I think this is illusory, resulting from the 



