OF ACULEATE HTMEKOPTEEA. 115 



from North America ; not a single species has yet been found in 

 India, China, the Philippines, or in any of the islands in the East- 

 ern Archipelago. 



The geographical distribution of the parasitic Bees, as might be 

 expected, is apparently regulated by the distribution of the genera 

 upon which tliey are parasitic. The genus Nomada, parasitic prin- 

 cipally upon the Andrenae, is found wherever the latter genus 

 occurs ; Nomada is consequently very rare in India and in the 

 Eastern Islands : a few species have been discovered, these proba- 

 bly being the parasites of the genus Nomia. Mr. Wallace discovered 

 two species ; these, together with two from Northern India, one 

 from North China, and one from the Philippines, are all at present 

 recorded from the East ; about fourteen are known from Algeria, 

 and twelve from North America. 



Ccelioxys, the parasite of MegacJiile, is cosmopolitan. Upwards 

 of fifty species have been described ; they are of course found in 

 all climates. Although no species has yet been received from 

 Australia, I am confident there will be several, the genus MegacMle 

 being common in that country. 



The genus Ctrocisa, although not consisting of more than ten or 

 twelve species, is very widely distributed. It does not occur in 

 England ; but three species are found in Europe : one of these, C 

 kistrio,ia also found in Algeria and in India. Three have been found 

 in South Africa, two in Australia, and one in North China. 



There are no less than eight genera of parasitic Bees peculiar 

 to South America : of these, Euritis, Melissa, Mesocheira, Thale- 

 stria, Ctenioschelus, Acanthopus, and Aglae are only fovmd in 

 Brazil ; of the genus Liogastra two species occur in Brazil, and 

 one in Mexico. 



The genus Melecta is also restricted in distribution ; nine species 

 have been described as European, one is Algerian, and two have 

 been recorded from Chili. 



In the family Scopulipedes, all of which are true working 

 Bees, we find the genera Eticera and Tetralonia, very closely allied 

 to each other, consisting of upwards of one hundred and twenty 

 species. The present known range of the former genus is Europe, 

 Egypt, and North Africa ; the type E. longicornis is common in 

 Europe and Algeria. The genus Tetralonia does not occur in Eng- 

 land ; but about twenty species are found in Europe ; it is also found 

 in North Africa, in India, China, and Australia ; several species 

 are found in Brazil and other parts of South America ; but no 

 species has yet been discovered in any of the islands of the East- 



