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V. Some observations on the Reproduction of the Hemiptera- 

 Cryptocerata. By C. Gordon Hewitt, B. Sc, The 

 University, Manchester. Communicated by Prof. 

 E. B. PouLTON, D.Sc, M.A, F.R.S. 



[Read February 7th, 1906.] 



During a short visit to the Sutton Broad Fresh-water 

 Laboratory in the Easter Vacation of 1905, T was able to 

 make a few observations on some points in the reproduc- 

 tion of three families of this subdivision of the Hemiptcra. 

 The Hcmiptera-Gryptoeerata form the second series of the 

 Hemiptera-Hcteroptera, and are interesting on account of 

 their aquatic habits. The species studied belong to the 

 families NepidiG, Corixidm, Naucoridai. 



As I am unaware of any account of the copulation of 

 Ncpa cinerea, and as this process is interesting in this 

 form, I shall describe it in detail. 



Nepa cinerea. 



This insect, the common water- scorpion, was fairly com- 

 mon in the dykes near the laboratory, and wishing to 

 obtain eggs at different stages of development, I placed a 

 number of males and females in an aquarium. 



Whether it was on account of the sexes being brought 

 into close proximity I don't know, but it was not long 

 before the males discovered the presence of the females. 



There are no preliminary amorous passages in the 

 courtship of A^ejM. This may possibly be accounted for 

 by several facts. The antennse, which play such an im- 

 portant part in the courtship of those insects whose habits 

 at this stage have been studied are too short to be of use 

 in these operations, so that we do not find any " caressing 

 of antennae." Nor do they appear to be of use for 

 perceiving the presence of the female, as far as can be 

 observed. 



The movements of the male Nc2)a are in accordance 

 with its usual habits. On perceiving a female, whether it 

 is by sight or by some sense of smell I cannot say, he 

 advances till he is within a short distance and then with 



trans, ent. soc. lond. 1906.— part I. (may) 



