Mr. M. E. Mosely on British species of Hydroptila. 179 



Berkshire ; one from the Usk at Senny Bridge, Breconshire ; 

 five or six from the R. Torridge at Sheepwash ; and Mr. K. J. 

 Morton has some examples which were taken, I believe, 

 towards the west coast of Ireland. 



Of cornuta, I have three examples from the Test; one 

 from the Thames at Hampton Court, and on examining the 

 collection at the Natural History Museum, found mixed 

 with sparsa, five or six examples collected by the Rev. 

 A. E. Eaton at Ringwood, on the R. Avon. A visit to this 

 district failed to discover any more. 



Basing the sequence on the scent-organ characters, one 

 would be inclined to arrange this little group in the order 

 cornuta, sparsa, angidata and simidans. 



Hydroptila cornuta, n. sp. 



Description of the (J. 



Expanse 1^ mm. Antemiae about 31-jomted, the head furnished 

 M'ith lobes shaped as in sparsa. 



The scent-organs are much simplified in form and appear to 

 consist merely of two groups of scent-hairs arising from the mem.- 

 branes which line the inner surface of each lobe. 



The dorsal plate resembles that of sparsa, but the extreme angles 

 of the plate are produced to form slight spxirs. Towards the base 

 of the plate there are well-marked projections on each side. The 

 two side processes arising from the 9th segment are longer and more 

 slender than those found amongst other members of the group. 

 The penis is as usual bent round at right angles towards the apex. 

 The inferior appendages resemble those of simulans, but the dark 

 warts towards the extremities develop into claw-like spurs. 



The ventral plate is deeply excavated in the centre of the upper 

 margin. 



H. angulata, n. sp. 



Description of the ^. 



Expanse 6| mm. Antennae about 32-jointed. 



The scent-organs closely resemble those of simulans, with the 

 slight variations mentioned above. The lobe differs considerably. 

 In simulans it is acorn-shaped with the acorn portion much longer 

 than the cup. In angulata the areas of the acorn and cup are about 

 equal and the length and breadth of the lobe are approximately the 

 same. 



The margin of the dorsal plate is difficult to make out. It 

 closely resembles that of simulans, but the extreme angles of the 



