I8 9 4.] 



THE BRITISH NATURALIST. 



137 



the buds. So far as is known at present, these insects are plant feeders, 

 and I merely mention the fact that it may not be lost sight of. 



In conclusion, I beg to thank Mr. A. T. Gillanders for the liberal 

 supply, from time to time, of infested shoots ; and also Mr. John 

 Pickering, of Poole Hall, Cheshire, for kindly forwarding a number of 

 infested bushes. The latter were planted at the rear of our Museum, 

 thus affording every opportunity of observing the disease. 



SOME CURIOUS AQUATIC LARVAE. 



BY GEORGE SWAINSON, F.L.S. 



(Continued from page 110.) 



The reason of our particular interest however, in the larva of 

 Chivonomus dor salts, was its very striking resemblance in all but colour 

 to the marine annelid Campontia cruciformis , of Johnston, which had 

 several times been captured on sea-weed and Zoophytes ; for it is now 

 certain that McLeay's guess was correct, and that this reputed marine 

 worm is the larva of a Dipterous fly. We have several specimens of 

 this form which we have mounted and stained with picro-carmine, and it 

 is almost impossible to distinguish them, even under the microscope, from 

 C. dorsalis. The mandibles, antennae and the two pairs of false feet or 

 pro-legs with horny hooklets, the intestinal canal, and lastly the two 

 pairs of long respiratory retractile tubules which the larva can protrude 

 from the eleventh segment, made it no longer possible to doubt that 

 Campontia was the larva of a marine midge of the Chivonomidce family. 



FIG. I CAMPONTIA CRUCIFORMIS. MARINE LARVA OF MIDGE. 



Thalassomyia Frauenfeldi of Schiner. 



The great difference when alive is in the colour, for instead of the 

 bright red of the u Harlequin " or Bloodworm you have in Campontia a 

 transparent sea-green colour. In fact the hcemoglobin which gives the 

 blood plasma in the " Harlequin" larva its beautiful tint, is replaced in 

 the marine form by a light sea-green pigment with which the fat cells 

 are coloured. 



On one occasion when out dredging with a few members of the 

 Manchester Microscopical Society, off Spanish Head, Isle of Man, a 



