I HAVE the satisfaction of again referring my readers to the 

 followino- works for the histories and descriptions of these 

 bees, viz. Reaumur, torn. 6, Mem. 3; and the Monographia 

 Apwn Anglia^ vol. 1. p. 178, and vol. 2. p. 260, from whence 

 we learn that they build their nests upon the uneven surface of 

 walls, and construct their cells of mud which has caused them 

 to be called Mason-bees. Although Osmia is nearly related 

 to Megachile, there are considerable differences in the trophi, 

 the most important of which is the 4-jointed maxillary palpus ; 

 and there are external characters, such as the longer antenn£e 

 and more woolly bodies of the males, and the more ovate and 

 convex bodies of the females, which will be found useful to 

 distinguish them. 



In addition to those described by Mr. Kirby, I have had 

 the good fortune to discovei* two others which appear to be 

 nondescripts. The genus may be arranged in the following 

 order : 



1. O. hirta Foiirc. — Leaiana Kirhy. August and beginning 



of Sept. Thistles, Suffolk, and Isle of Wight. 



2. spinulosa A7rZ>j/, /aZ). 17. y^ 1 &2. August. Sand and 



chalk pits near Ipswich, Suffolk. 



3. leucomelana Kirhy. Amongst pines, and on flowers of 



Dandelion : Suffolk. July and August : upon Cen- 

 taurea, and under the cliffs at Dover. 

 4!. caerulescens Linn.^ Panz. 65. 18. Jem. — aenea Panz. 

 56, 3, masc. July ; in chalky and sandy places. 



5. parietina Curtis Brit. Ent. pi. 9,22. f cm. Beginning of 



June ; flying about walls near Ambleside. 

 With the male of this bee I am unacquainted ; the female 

 resembles in size and colour the same sex of O. hirta, but the 

 pubescence of the thorax is ferruginous, and the hair with 

 which the underside of the abdomen is clothed is black. 



6. Tunensis Fah. — aurulenta Panz. 63. 22. fem. July; 



on clayey banks. 



7. bicolor Schr. — fusca Panz. 56. W. fern. — haematoda 



Panz. 81 . 20. masc. P End of June ; Darent Wood. 

 July ; gardens and sunny banks. 



8. atricapilla Nob. — I have only a female of this insect 



taken by myself; it is black, the thorax and base of 

 abdomen fulvous. 



9. bicornis Limi. — fronticornis Panz. 63. 20. Jem. var. — rufa 



Pa7iz. 56. 10. 7nasc. — cornuta Lat. March, April, 

 May ; sandy places. The males are plentiful upon 

 paling at Hampstead, Battersea, and other places 

 near London, and also upon flowers. 

 The plant is Salvia vcrbcmaca (Wild Clary). 



