ART. 20 THE APHID GENUS AMPHOROPHOEA MASON 3 



being very prominently swollen, others being very slender, but at 

 the same time, plainly dilated. There is a distinct distal flange in 

 all species. One group of species has the tip of the cornicles very 

 conspicuously reticulated. Another group has no reticulations, but 

 often two or more lines or imbrications. Certain species are inter- 

 mediate between the reticulated and imbricated ones. Some have 

 small scales or imbrications over most of the length of the cornicle, 

 while in others these organs have an almost smooth surface. 



The shape of the cauda varies from those that are strongly con- 

 stricted to those that are conical. The number of hairs on the cauda 

 differs in the different species, but, as a rule, there are 2 to 4 sets of 

 lateral ones. 



Tubercles are not conspicuous in the genus as a whole, but several 

 species show prothoracic, lateral ones. A few species have them on 

 the lateral margins of the abdominal segments. One species has two 

 dorsal ones on the head and two on the dorsum of the protliorax. 



Intermediates between the alate and apterous forms appear to be 

 fairly common in the genus as I have seen them in three species, 

 nahali Oestlund, sensoriata Mason, and essigwanai, new name. 



The type of the genus is Amphorophora ampullata Buckton, which 

 is described in British Aphides.^ It was taken on the fronds of 

 Cystopteris montana. The type slide still exists in the British Museum 

 and contains three apterous viviparous females. A very similar 

 species was taken from ferns on the American continent, and drawings 

 of it were sent to Frederick Laing for comparison. He says in private 

 correspondence that in all of the type specimens of ampullata "the 

 sensoria reach nearly the length of Segment III and number from 

 30-34." The species from this continent, he says, seems to be the same 

 as one which he reared in England from a fern and the same as Van 

 der Goot described as ampullata Buckton.^ I learn from correspond- 

 ence with Professor Oestlund that his 1887 description of ampullata 

 Buckton is of the same species. William's ampullata Buckton? 

 (1910) is very probably the same, but I can not tell from his descrip- 

 tion, and his specimens seem to be lost. There is also in the National 

 Collection the same form from Takahashi. It is probable that all 

 references in literature to ampullata Buckton, except those cataloguing 

 the original description, refer to this new form. Laing writes that 

 he had given to this new form a provisional varietal name, but sug- 

 gests that the writer fix the status as he thinks best. In view of the 

 differences in the number and position of the sensoria on Segment III 

 of the apterous viviparous female, it is my opinion that it is entitled 

 to standing as a distinct species, and it is described in this paper as 

 A. laingi, new species. A. ampullata Buckton, therefore, at present is 

 known only from the type slide. 



'Vol 1, p. 187. 



<Beit. Z. Kennt. tier Holland, Blattlauso (191). 



