THE ENTOMOLOGIST 



Vol. XLV.] FEBEUAEY, 1912. [No. 585 



A NEW SPECIES OF PHASMID^ OF THE GENUS 

 PRISOPUS, CONSIDERED ESPECIALLY IN EEF- 

 ERENCE TO THE SUPPOSED AQUATIC HABITS 

 OF THE GENUS. 



By C. J. Gahan, M.A. 



(Published by Permission of the Trustees of the British Museum.) 



Prisojms is a genus of Phasmidae which, owing to the sin- 

 gularity of its form and structure, cannot very well be described 

 either as a " stick " insect or as a " leaf" insect; but it is one of 

 exceptional interest, inasmuch as it was believed to live under 

 water, and to be eminently adapted by its structure for that 

 mode of life. The species of the genus inhabit tropical America, 

 and those that are known are few in number and apparently 

 rare, very few specimens having yet found their way into 

 public or private collections. 



I was glad, therefore, to be able to recognize as a member of 

 this rare and interesting genus an insect which was recently 

 brought to the British Museum and shown to me by Mr. P. G. 

 Fisher, who discovered it at Xapury, a township on the River 

 Acre, in the Amazon Valley. And I was still more pleased when 

 Mr. Fisher very kindly offered to present it for the Museum 

 collection, where we found we had no species quite like it. From 

 investigations which I have since made, the species appears to 

 be new ; so I have ventured to name it Prisopus fisheri in honour 

 of its discoverer. A more detailed description of this new species 

 is given below. Here I wish more particularly to call attention 

 to certain points' about it which serve to throw a light upon the 

 supposed aquatic habits of Prisopus ; and to say something also 

 in reference to another Phasmid genus, Cotylosoma, to which 

 similar habits have been attributed. 



When first I saw the specimen brought to me by Mr. Fisher, 

 it struck me at once as being an extremely good and very 

 beautiful example of protective resemblance. And then, though 

 I felt there was no need for the question, I asked him where he 

 found it. The answer was very much as I expected. Mr. Fisher 



ENTOM. — FEBRUARY, 1912. E 



