BEES IN BRITISH MUSEUM. 339 



Table A. 



This table was devised to show the wide distribution of certain 

 striking types, which do not seem likely to have originated inde- 

 pendently from more ordinary .forms. In particular, one notices the 

 similarity of certain species on the two sides of the Atlantic in 

 tropical regions. This, and the fact that of all bees Megachile is, 

 perhaps, most widely spread on oceanic islands, lend support to the 

 idea that the. bees are distributed by means of floating trees contain- 

 ing their nests. It is especially interesting to find that all Hawaiian 

 genera of bees are such as nest in stems or tree trunks, the ground- 

 nesting genera being absent. 



Wings orange, the outer margin, more or less, broadly blackish 1. 



Wings with the basal half hyaline, and the apical half fuliginous; metathorax 

 and first abdominal segment covered with white hair (Gambia). 



maxillosa Guer. 

 Wings fuliginous, or at least very dark ; insect coal-black 4. 



1. Black, with short black hair ; scopa black 2. 



Abdomen largely red, or orange-red haired 3. 



2. Large, fully 20 mm. long; clypeus with a large median tubercle in 9 (Borneo). 



tubercnlata Sm. 



Smaller, length about 16 mm.; clypeus without an apical median tubercle in 



9 (Nicobar Is.) fulvipeunis Sm. (T.). 



3. Abdomen with short rust-red hair all over (West Indies). 



rufipeiiiiis (Fahr.). 

 Abdomen with only the basal half covered with orange-red hair (Sierra 



Leone) ruiipes (Fabr.). 



l.l/. c'nicta (Fabr.) from Sierra Leone has the abdomen much more like that of 



rufipennis, but the wings are much less orange.) 



4. Species of Ceram lachesis Sm. 



Species of India anthracina Sm. 



Species of the United States ; abdomen broad ; scope black 5. 



5. Punctures of scutellum and hind part of mesothorax larger and more separa- 



ted ; wings darker and longer; second s. m. longer. 



xylocopoides Sm. (T.). 

 Punctures of scutellum and hind part of mesothorax smaller and closer; 

 wings shorter, and not so dark ; second s. m. shorter and smaller. 



morio Sm. 



Table B. — Mexican species. 



Hair of vertex and thorax above partly or largely black or blackish 1. 



Hair of vertex and thorax above ochreous or fulvous, without black 6. 



1. Male; abdomen ending in two widely-separated spines or teeth ; anterior tarsi 



simple foitleutata Sm. 



Females ; abdomen broad (not very in bipartita) 2. 



TRANS. AM. ENT. SOC. XXXI. .-EI'TEMBEB, 1905. 



