EXPLANATION OF PLATES. 



All the figured specimens are preserved in th.e British Museum, 

 their registered numbers being quoted in square brackets. The 

 figures are drawn natural size, except in one or two cases where 

 the enlargement is stated. "With the exception of PI. I. Figs. 

 1 and 2, PI. X. Fig. 3, and PI. XI., all the specimens are 

 from the Rufford Collection. 



