DIPTERA. 157 



from two to three inches in length, and rather better than 

 half an inch in diameter. Short malformed leaves diverged 

 from the gall in all directions. The larva, which was so well 

 protected and provided with food, was about half an inch 

 in length, elongate ovate, tapering at each extremity, white, 

 somewhat shining and translucent. 



VIII. On the sand-hills at Land's End, near Whitby, Trlti- 

 cum junceum is an abundant plant, and at the commencement 

 of August I found the young shoots near the ground attacked 

 by a Dipterous larva, causing an oval gall-like swelling 

 very similar to the one just described. This gall-like 

 swelling was an inch to an inch and half long, very suc- 

 culent, and was composed of the thickened basis of the 

 sheathing leaves. The larva was about one-eighth of an inch 

 long, very smooth and glossy, whitish and translucent, sub- 

 cylindrical, somewmat tapering at the extremities, with a 

 row of short tubercles on the back, one on each joint, com- 

 mencing with the second and terminating with the eighth 

 joint. 



IX. At Birch Wood, the 7th July, I found the stems of 

 Hievacium umbellatum attacked by a Dipterous ? larva, 

 causing a very hairy pear-like swelling, from which pro- 

 ceeded a number of stunted, well-formed leaves. Some of 

 these gall-like swellings were more than half an inch in 

 diameter, and fully an inch in length. They occurred at 

 the apex of the steins. 



X. In a shady part of a wood near St. Leonards, the 

 stems and rhizomas of Stachys sylvatica were found in the 

 beginning of September, by my son, covered with small gall- 

 like excrescences about the size of a pea. They occurred in 



