CEYLONESE APHIDES. 
185 
fine plates. As I was able to verify on specimens of Ceratovacuna 
lanigera kindly sent to me by Prof. Busse, Ceratovacuna must be 
treated only as a synonym of Oregma , although the two species 
O. bambusce and O. lanigera are very distinct forms. The des¬ 
cription given by Zehntner is, I may say, a model in its kind, and 
it is therefore not necessary that I here describe again O. lanigera , 
of which I figure only the antenna of winged female for compari¬ 
son with O. bambusce. 
The synonymy of the genus is thus :— 
Oreoma, Buckton, Ind. Mus. Notes, III., p. 87. 
Ceratovacuna , Zehntner, Arch, voor de Java-Suikerindustrie,V., 
p. 553 (1897). 
(1) O. bambusce , Buckt., Ind. Mus. Notes, III., pp. 87 and 108. 
(2) O . lanigera , Zehntner, Arch. Jav. Suikerind, V., Aflev. 10, 
p. 553 (1897) ( Ceratovacuna ); Mededeel van het Proof station voor 
Suikerriet in West Java, No. 49, or Arch. Jav. Suik.-ind., VIII., 
Aflev. 20 (1900) ( Ceratovacuna ). 
Apterous Viviparous Female , 
Body broadly ovate, rather convex ; the younger specimens are 
more elongated, oval; of a dark grayish colour, somewhat pul¬ 
verulent, a tuft of white wool at end of abdomen. 
Gephalothorax very distinctly separated. Segmentation of the 
abdomen distinct on larvae only. 
Front furnished with two teeth-like processes, which are hardly 
more remote from each other than from basis of antennae; the 
most developed females have the processes smaller, nearly so long 
as the first antennal joint. Larvae and young specimens present 
them much longer, nearly of equal length to the cephalothorax, 
very distinctly curved. Eyes of very small size. 
Antennae of equal length as the cephalothorax (or slightly 
longer); the fifth joint and apex of fourth black or dark ; they are 
inserted on short frontal tubercles. First joint hardly longer than 
the second, and slightly broader; second slightly constricted at 
base ; third, the longest, so long as the following two united, much 
longer than the two preceding, nearly cylindrical; fourth nearly 
so long as half the third ; fifth slightly longer than fourth, after 
middle gradually narrowing, with a short appendix. (Buckton 
figures the fourth joint longer than the third.) Rostrum very 
short. 
Legs robust, posterior tibiae long ; tarsi two-jointed, first joint 
very short, second much longer (the first is therefore not so long 
as the second, as Buckton draws it!). 
