2 K. Takahashi. 



Oregina formosana n. ap. 



0. oplismeni n. sp. 



0. J:.os7iunensis n. sp. 



0. alexandcri n. sp. 



0. jjseudomontana n. sp. 



Ceratapliis /ormosanns n. sp. 

 The Macrosiphmn sjjp. seem to be new to science, but the author hesitates to 

 give new names to them, sinee their winged forms liavc never been collected. Tlie 

 new Japanese species dealt with in the present paper are Macrosiphum esahii, 3f. 

 smilaceti, Myzus rJiois, Pdtchia spiraeae and Oregma Japonica. 



The results of further studies will be published in tlie fourth- report of tliis 

 series of papers. The type specimens are preserved in the collection of the cntomoln- 

 gical laboratory of this Department. All the drawings accompanying this paper 

 were made by the author. 



The author wishes to express his sincere thanks to Dr. T. Shiraki, Chief of 

 the Section of Economic Zoology of this Department, for his kind h(!lp in comp- 

 leting this report. The author is greatly indebted to Prof. Dr. C. P. Alexander 

 of the United States of America for liis kindness in correcting many errors in 

 English in the manuscript of this paper, and Oregma alexanderi n. sp. is dedicated 

 to him. 



The author must express his hearty tlianks to Prof. Niijima and Messrs. 

 Knwayama, Esaki, Hori, Yokoyama, Kisliida, Takeuch', Kurisaki, Uye, and others 

 for the valuable aphid material sent to liim. Ijastly the author expresses his most 

 cordial thanks to the Hon. Prof. Dr. K. Oshinia, Director of the Department of 

 Agriculture, Gevernment Research Institute, for iiis kindness in publishing this 

 ]>aper. 



Notes on the morphology of the nymphs of Aphidinae. 



Ecdysis 

 The aphids, wliether winged or wingless, usually moult four times before rea- 

 ching maturity and, as a rule, have four nymphal instars, but there are certain 

 exceptions to this. Davis records a case where an apterous form of AjJiis maid!- 

 rad.icis Forbes gave birtli to six young, then moulted, became winged and produced 

 twenty-one more young. According to Haviland, Myztis ribis L. sometimes shows 



